A bulletin from the National Terrorism Advisory System warns of a "heightened threat environment in the United States" following the U.S. military strikes on Iran's nuclear sites. The bulletin, obtained by CBS News and dated Sunday morning, June 22, does not note any current specific threats, but warns that "low level cyber attacks against US networks by pro-Iranian hacktivists are likely, and cyber actors affiliated with the Iranian government may conduct attacks against US networks." CBS News