Less than two weeks after UnitedHealthcare CEO Brian Thompson was gunned down on the streets of midtown Manhattan, his alleged assassin Luigi Mangione has been greeted not by universal condemnation for the brazen violence – but rather, a surge of enthusiastic support online for his so-called vigilante justice.

The Center for Internet Security (CIS), a nonprofit focused on cybersecurity that partners with government and law enforcement, released a new threat assessment bulletin warning that online support for the alleged shooter risks encouraging copycat attacks.

“Overwhelming bipartisan support for the attack” across social media “has resulted in several narratives encouraging similar violent activities directed at other healthcare executive teams,” CIS analysts said.

“The narratives supporting Mangione’s targeted attack likely serve to encourage like-minded individuals, particularly as Mangione continues to be viewed by the public as an ‘American hero’ and sympathetic figure,” CIS’ bulletin said.