This is the same nonsense we see from almost all feminists and SJWs. Some trolls, possibly not even gamers, tweet her death threats and nasty stuff in order to illicit a response, she's either not savvy enough with the internet and too naive to recognize this or deliberately leveraging these threats to spin a narrative in order to gain publicity.
The simple fact is that most people with an online presence who make controversial content attract trolls and angry people, this is nothing specific to her if you go look at anyone that's big in the public eye you'll find they get the same thing, male or female, gamer or not. It's only the SJWs and more predominantly the feminists who use this to spin a threat narrative.
It should be noted that Anita is a liar and a con artist, she lied about being a gamer and was caught on video admitting she wasn't a gamer and doesn't even like games -
https://www.youtube.com/watch?v=gcPIu3sDkEw
She scammed $160,000 on kick starter to make a series of 12 videos on July 2012 and over 2 years later we still only have 5, there has been no notable change in quality in her videos to those made prior, for free.
She's also a thief and stole artwork from other people without their permission-
http://cowkitty.net/post/78808973663/you-stole-my-artwork-an-open-letter-to-anita
As well as reusing lets play footage from other youtubers without their permission -
https://www.youtube.com/watch?v=YvwiYmVhW94
She's been found to be extremely dishonest, disables comments on her videos to stop legitimate discussion of her work, she also disables voting and the few times it has been temporarily allowed the scores have been overwhelmingly negative.
All her work to date has been thoroughly debunked by literally hundreds of youtubers.
She asserts tropes as contributing to real world issues for women but has not cited any published, peer reviewed, scientific papers which link the effects of gaming (or any media, actually) to changes in real world.
Her dissertation for her degree was pulled offline when critics found many holes in her work.
Her videos are largely cherry picked material and promote a sexist look at video games, whenever she shows game that have violence or sexism against women she fails to acknowledge times when this happens to male characters. She continually references abuse against women and not abuse against people, in her world view men aren't seen as people only women are, this is a fairly normal tactic by modern feminists.
She's also extremely hypocritical, she finds work of media about her, such as the beat up Anita game as unacceptable, yet has no problem engaging in fantasy media where she endorses the death of Randy Pitchford -
http://femfreq.tumblr.com/post/58161053721/spider-man-recruits-the-help-of-anita-sarkeesian-to
The extent of her death threats are nothing more than twitter trolling, we've seen many feminists before her play the same card and blow out of proportion this kind of behaviour, of the long line of feminists who play this card, people like Rebecca Watson for example, none of them actually have suffered any of the content of the threats, if they thought for a second that these kind of despicable threats were real and posed real danger, they'd stop making content and probably be given new identities by law enforcement. We all know they don't take this seriously and they're using this as an "example" to prove their points, which is another disgusting lie because most gamers aren't like that of the millions of gamers only a handful of bad apples elevate to threat level tweets, arguably most do it for trolling/effect.
Anita is a dishonest menace to gaming and people need to read any news surrounding her with a grain of salt and a huge serving of perspective. If media outlets made all death threats over twitter news worthy we'd all drown in "news" but because it's a feminist suddenly we all care?