On April 3, 2018, an attack against YouTube headquarters in San Bruno, California, left four people shot and the shooter dead by her own hand. She called herself a "vegan vlogger."
Police identified the woman in Tuesday's shooting as San Diego resident Nasim Najafi Aghdam, who was in her late 30s. She may have been a disgruntled user of the video-sharing site.
Aghdam wounded three people at the campus in San Bruno, south of San Francisco, then turned the gun on herself, authorities said. A fourth person suffered an ankle injury while escaping the gunfire.
Aghdam appears to have been a prolific, longtime social media user. She lists four YouTube channels -- one in Farsi, one in Turkish, one in English and one devoted to hand art. It also lists an Instagram page that focuses on vegan life and animal rights.
Nasim Najafi Aghdam's grievances against YouTube appear to be centered around censorship and revenue.
"There is no equal growth opportunity on YOUTUBE or any other video sharing site, your channel will grow if they want to!!!!!" one post reads. "Youtube filtered my channels to keep them from getting views!"
On a YouTube channel, the same woman described herself as a vegan bodybuilder and an animal rights activist. By Tuesday night, the account had been terminated, with a YouTube message citing "multiple or severe violations" of its policy.
The postings are not limited to YouTube. Videos on several social media platforms include posts on animal rights, vegan lifestyle and the political system in Iran. Others include a bizarre mix of musical parodies.
YouTube was founded in February 2005 and quickly became a major site for online videos. It was later purchased by Google.
More than 1,100 people work at the YouTube office in San Bruno, about 10 miles from San Francisco.
As questions remain on the motive, police have said there's no evidence the shooter knew the victims or that they were specifically targeted.
On January 30, 2006, Jennifer San Marco visited her former place of employment, a postal distribution center in Goleta, California, and fatally shot six employees after killing a one-time neighbor. She then killed herself.