Twitter’s crackdown on the Islamic State is hindering its social media use, but its supporters are switching to other messaging platforms, according to a report released by GW’s Program on Extremism Thursday.

Audrey Alexander, a researcher in the program, analyzed 845,646 tweets from 1,782 English-language accounts sympathetic to ISIS for more than a year between February 2016 and May 2017. She found activity on the accounts had decreased in part because Twitter had begun shutting down and silencing accounts in support of ISIS on its website. Alexander said the move, while positive on the surface, could inhibit law enforcement’s ability to track the terrorist group.

Alexander said the shift away from Twitter was already happening before the site launched its effort to silence pro-ISIS accounts. But the study found that ISIS sympathizers were switching to messaging sites that offered more encrypted communication.

“Our study reveals that despite mounting pressures, IS sympathizers are skilled problem solvers in the digital sphere,” she said in the release. “Rather than ruminating over losses, angered adherents fight to be heard, either on Twitter or other platforms.”

The study found that Twitter conversations between ISIS sympathizers were largely ineffective and some of the biggest spikes in activity were about non-ISIS related events like the foiled 2016 coup attempt in Turkey and last year’s U.S. presidential election.

Overall, the study argues that the government should not rely on social media providers to tackle ISIS activity on social media and that providers should examine alternate methods of fighting extremist groups.

“Swift efforts to silence IS supporters on social media may inadvertently produce side effects that challenge the efficacy of policymakers and law enforcement in preventing threats posed by violent extremists,” Alexander said in the release.