The widow of a man killed in an attack on a Jordanian police training center filed a lawsuit against Twitter on Wednesday in San Francisco federal court, accusing the company of giving a mouthpiece to terrorist groups like ISIS–which took credit for the attack. The suit argues that ISIS has used Twitter to attract new recruits and to disseminate propaganda, and that the site has “knowingly or with willful blindness” aided terrorists as a result.

“Without Twitter, the explosive growth of ISIS over the last few years into the most-feared terrorist group in the world would not have been possible,” the complaint reads.

Tamara Fields, who lives in Cape Coral, Florida, is requesting unspecified compensation for her husband Lloyd “Carl” Fields Jr.’s death in November.

As Fast Company wrote recently, Twitter’s policy on hate speech regulates content that encourages violence or threats “on the basis of race, ethnicity, national origin, religion, sexual orientation, gender, gender identity, age, or disability.” But its rules are far less stringent than that of Facebook, which aims to remove any content that qualifies as hate speech.

“While we believe the lawsuit is without merit, we are deeply saddened to hear of this family’s terrible loss,” Twitter said in a statement to Bloomberg. “Violent threats and the promotion of terrorism deserve no place on Twitter and, like other social networks, our rules make that clear.”

[via Bloomberg]