The family of a Florida defense contractor killed in a November terror attack while training security forces in Jordan is suing Twitter, claiming the company has knowingly allowed terrorist groups such as ISIS to use its social network to spread extremist propaganda.

According to court documents filed Wednesday in the U.S. District Court for the Northern District of California in San Francisco, Lloyd "Carl" Fields Jr. was killed by a Jordanian police captain he was training at the International Police Training Center in Amman, which is operated and funded in part by the U.S. State Department. ISIS took credit for the attack, which also took the life of another American contractor, according to the lawsuit.

The lawsuit blames Twitter in part for the attack, claiming it allows extremists to recruit and spread violent ideology on its platform.

"For years, Twitter has knowingly permitted the terrorist group ISIS to use its social network as a tool for spreading extremist propaganda, raising funds and attracting new recruits," the suit says. "...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."

According to the lawsuit, ISIS has an estimated 70,000 Twitter accounts, at least 79 of which were "official," and it posted at least 90 tweets every minute.

A Twitter spokesperson issued the following statement on Wednesday:

"While we believe the lawsuit is without merit, we are deeply saddened to hear of this family's terrible loss. Like people around the world, we are horrified by the atrocities perpetrated by extremist groups and their ripple effects on the Internet. Violent threats and the promotion of terrorism deserve no place on Twitter and, like other social networks, our rules make that clear. We have teams around the world actively investigating reports of rule violations, identifying violating conduct, partnering with organizations countering extremist content online, and working with law enforcement entities when appropriate."

This isn't the first time Twitter has been accused of offering a venue for terrorists. In December, the government of Turkey fined Twitter for refusing to remove content deemed "terrorist propaganda." Twitter responded by filing a lawsuit saying the fine was illegal.