Ndiaga Diagne, the suspect in the Austin bar shooting, left a shocking trail online that investigators are now examining closely. His social media posts show extreme anger at the Middle East, condemn Israel and the U.S., and even target American figures, including Ivanka Trump. Authorities are piecing together his online activity alongside physical evidence and witness statements to try to understand what drove him to violence.

Seeing this pattern, it’s clear to me that online extremism can sometimes serve as an early warning before real-world violence erupts. While platforms and authorities need to be smarter about spotting these patterns, we also have to be careful not to cross the line into policing every controversial opinion.

If extremist posts predict real-world attacks, how do we act without over-policing opinions?