Aghdam shot and wounded three people at YouTube’s headquarters on Tuesday before fatally shooting herself. The three people with gunshot wounds, and a fourth who reportedly injured their ankle while fleeing, were taken to a the hospital for treatment.

In a statement, the San Bruno Police Department said it was investigating Aghdam’s motive. “At this time there is no evidence that the shooter knew the victims of this shooting or that individuals were specifically targeted,” the cops said.

Aghdam had a website on which she railed against the Google-owned platform’s treatment of the videos she uploaded. “YouTube filtered my channels to keep them from getting views!” she wrote, claiming that the platform used age restrictions on her Farsi channel “to reduce views and suppress and discourage me from making videos.”

Last year YouTube started “demonetizing” videos with offensive content by removing the ability for their creators to generate advertising revenue. Aghdam’s site railed against this practice, claiming she got just $0.10 in revenue for more than 360,000 views on one of her channels.

The shooter’s channels have now been removed from YouTube—their subject matter ranged from veganism and animal rights to clothing design and exercise routines. The platform says the channels were “terminated due to multiple or severe violations of YouTube’s policy against spam, deceptive practices and misleading content or other Terms of Service violations.” Her Facebook page also appears to have been deactivated.

“There are no words to describe how horrible it was to have an active shooter @YouTube today,” tweeted YouTube chief Susan Wojcicki. “We will come together to heal as a family.”

There are no words to describe how horrible it was to have an active shooter @YouTube today. Our deepest gratitude to law enforcement & first responders for their rapid response. Our hearts go out to all those injured & impacted today. We will come together to heal as a family.

— Susan Wojcicki (@SusanWojcicki) April 4, 2018

It is exceedingly rare for a mass shooter to be a woman. Of 220 “active shooter” incidents in the U.S. so far this century, just nine involved female shooters, according to FBI figures.