A German artist who beamed the words “United Stasi of America” onto the wall of the U.S. embassy in Berlin says Washington’s spy methods make the former East German secret police look like boy scouts.

A video of Oliver Bienkowski’s artwork is fast becoming a hit on the Internet in Germany, tapping into widespread outrage over U.S. surveillance programs revealed by fugitive ex-National Security Agency (NSA) contractor Edward Snowden.