Gessen was born into an Ashkenazi Jewish family in Moscow. In 1981 Gessen moved with her family to the United States. She returned in 1991 to Moscow. She holds both Russian and US citizenship. Her brothers are Keith Gessen, Daniel Gessen and Philip Gessen.
Gessen is openly gay and an activist for the rights of sexual minorities. She served as a member of the board of directors for the Moscow LGBT rights organization "Triangle" from 1993 to 1998.
She has written on LGBT rights and Russian affairs. She writes in both Russian and English, and has contributed to The New Republic, New Statesman, Granta, Slate and Vanity Fair, and US News & World Report.
I've seen her byline a lot at NYTimes.com.
... Gessen covered Pussy Riot and their punk rock protest against Putin in her 2014 book Words Will Break Cement: The Passion of Pussy Riot. 
She was dismissed from her position as the chief editor of Russia's oldest magazine, Vokrug Sveta on 1 September 2012 after she refused to send a reporter to cover a Russian Geographic Society event featuring President Putin, claiming that it had become a mouthpiece of Putin's government.
So, she was then put in charge of a mouthpiece of Obama's government:
In September 2012, Gessen was appointed as director of the Russian Service for Radio Liberty, a US government funded broadcaster based in Prague.
Shortly after her appointment was announced and a few days after Gessen met with Russian President Vladimir Putin, more than 40 members of Radio Liberty's staff were fired. Radio Liberty also lost its Russian broadcasting license several weeks after Gessen took over. Gessen's role in both of these events is unclear but has caused controversy.
The conservative Heritage Foundation, which of course is all for Radio Liberty, is highly critical of Gessen's takeover of RL's Russian Service, which involved her bringing her pals in (presumably at the expense of Heritage's pals): "Most importantly, Gessen, who was a consultant to RL for reorganization, managed to land the coveted RL Russian service directorship and then led the service straight into its nosedive by eliminating experienced broadcasters and bringing in with her a team of like-minded elitist print journalists, with little or no experience in radio broadcasting."
More from Wikipedia on Masha Gessen:
In December 2013 she moved to New York to avoid legislation in Russia that bans "homosexual propaganda".  
... She is however opposed to the existence of marriage at all, and advocates for the fundamental change of the institution of marriage, including her three children being legally able to have five parents. 
The oligarch Boris Berezovsky was found dead in his home outside of London over the weekend, either a suicide or a heart attack. He was depressed over losing a lawsuit to his old business associate, Roman Abramovich; had failed to secure what he thought was his rightful property after the death of another, much closer associate, Badri Patarkatsishvili; was losing a decade-long battle to his former protege, Vladimir Putin; and was also, on top of all that, apparently running out of money. With him he took many of the secrets, and insights, and schemes, that nearly destroyed Russia in the decade after the Soviet Union fell apart.
Berezovsky wasn’t just an oligarch: he was the first oligarch. He is sometimes referred to slightingly as a “former used car salesman”—this is a kind of joke. In fact Berezovsky was an accomplished mathematician, a corresponding member of the Soviet Academy of Sciences, with a specialization in game theory. ...
The incredible success of Berezovsky—he would have become a multi-millionaire when he started moving hundreds of thousands of cars, and a billionaire, at least on paper, when he won the Sibneft oil conglomerate in the rigged loans-for-shares auctions of 1995—represented the colossal failure of his generation of Russian liberals. He may not have been the best of this generation, morally speaking, but he may well have been one of the brightest (for a Jew of that generation to have made it as far as he did in Soviet academia was a tremendous accomplishment), and in certain important ways he believed what they believed: that capitalism was virtuous; that because capitalism was virtuous, those who succeeded at capitalism were the elect, and those who failed at it were the damned; that, politically speaking, all that was required for the liberation of the Russian people, after three hundred years of oppression, was to open the windows and let the free market in. What all this led to, in fact, was the enrichment of a very few and the immiseration of the populace, the reduction of life expectancy for Russian males by nearly a decade, and, as of last year, nearly a million suicides. And now it seems possible that Berezovsky is one more.
What was criminal capitalism in Russia actually like? On the most fundamental level it was a series of protection rackets. If you sold vegetables on the street corner, eventually you’d be approached by some guys in leather jackets who would demand protection money. If you didn’t pay, they upset your vegetable stand; next time, they beat you up. If you paid them, they protected you. They didn’t do this particularly well, but they would try; if some other group of guys in leather jackets came along and tried to shake you down, they’d tell them to lay off, and if they didn’t lay off, they’d fight them. There was a lot of fist-fighting in those days, and most of the guys in the protection rackets were boxers or karate or wrestling champions, including, occasionally, a former Olympian. ...
My father, a computer programmer who emigrated to the US in 1981, went into business in the 1990s with two of his old computer programmer friends who had remained in Russia. They did “import-export”—they brought things into Russia that were much cheaper to get abroad (the classic example of this was personal computers, which were nonexistent in Russia in 1991, though relatively plentiful in the West), and exported things that were cheaper to get in Russia than abroad, like timber. After a few good years, my father and his partners closed up shop when the Russian economy collapsed in 1998.
But my father had a great time; I suppose it was especially fun since he spent most of it in Newton, Massachusetts. He liked telling the story of how his partners got shaken down by a criminal gang. By this point they were an established business; they owned a beautiful old mansion right next to the Belarusskaya train station. But one day two men marched into the mansion and demanded protection payments. My father’s partner, a former computer programmer, explained that they already made payments to someone (which was true). The two gentlemen didn’t seem to care. They said they’d be back in two days for their money.
My father’s partner called the security firm that was supposed to be guarding him, otherwise known as his krysha, or “roof.” The krysha was run by a former police colonel. Other such groups were run by former KGB colonels. Others still were run by former (or current) gangsters. In any case they were now all in the same game. This former police colonel listened to the story and said he would make some inquiries. “If it’s the Georgians,” he said, “we can deal with it. And if it’s the Izmailovo group, we can talk to them. But if it’s the Chechens, we can’t help you.” ...
... In 1998 and 1999, Berezovsky’s position—at this point he was not only a rich man, but a frequent visitor to the Kremlin and adviser to Boris Yeltsin—became tenuous. ... Berezovsky saw this happening and came up with a plan. The mood of the country was nationalistic, even militaristic. The oligarchs (or liberals, as Berezovsky thought of them) needed their own nationalist candidate, and he found one in a short, unassuming former KGB officer named Vladimir Putin. He convinced Yeltsin to replace Primakov with Putin. ...
To his credit, Putin disappointed Berezovsky’s expectation almost as soon as he assumed the presidency. He tried to bring the oligarchs to heel. Whatever else he was wrong about—which was everything—in this at least he was right. These were men who had been handed immense industrial fortunes by a desperate government. They became billionaires overnight. But they had not built these companies. The companies had been built by Soviet workers over the course of decades—some of these workers believed that they were building Communism, some of them were prisoners of the Gulag. All of them worked for pennies. For the oligarchs to pretend like they had earned their fortunes was tremendously insulting to the millions of people who had built them in actual fact. The best and fairest thing to do would have been to nationalize the giant oil companies right then and there. But Putin is a bully and he tried to bully the oligarchs. He began police inspections of Gusinsky and Berezovsky, and soon they had both fled the country; Gusinsky quietly and forever, Berezovsky loudly and with a promise to return. The other oligarchs agreed to behave themselves. The exception was Khodorkovsky, who neither left nor agreed to behave himself. He ended up in prison.
... In recent years Berezovsky would often talk about how Putin was his biggest mistake—“I thought I knew people,” he would say, “but look at the mistake I made.” The implication being that if it weren’t for that one mistake, things would have turned out all right. But they had already not turned out all right, long before Putin. ...
I know that it’s a turn-on for Westerners, left and right, to pretend that big bad Putin ordered Berezovsky killed. The likelier scenario is more tragic and more internal: the self-reckoning of a man who had been given a magnificent mind, and limitless energy, and who devoted these, primarily, to destruction, speculation, and manipulation. With humor, panache, extraordinary inventiveness—but still.
Or is Keith Gessen just too reasonable for the purpose of waging World War G?