German artist Oliver Bienkowski projected the message, along with a picture of internet tycoon and online activist Kim Dotcom onto the US embassy in Berlin on Sunday night.
He was likening reported sweeping internet surveillance by Washington and London to spying by the former East German secret police. And while the image was projected onto the building for 30 seconds on Sunday night, the action has caused quite a stir.
An investigation has been launched into whether the action constituted “slander against the organizations and representatives of a foreign state,” the Berlin-based Der Tagesspiegel newspaper reported on Thursday.
Bienkowski's lawyer Fabian Eickstädt pointed out that the projection was onto the US embassy, which is technically US territory. "For me it is not even clear whether German law would apply," he said.
And Der Tagesspiegel said that a criminal case of slander could only be launched if the victim were to make a formal complaint. The US embassy told the paper it had no interest in a prosecution.
While Dotcom had no problem claiming the projection. "I defaced the U.S. embassy in Berlin with a truth-projection last night. 0Wned!" he tweeted. The video on YouTube has garnered nearly 80,000 hits.
Dotcom, a German national, is the founder of file-sharing website Megaupload that was shut down by US authorities who seek to extradite him on charges of racketeering, fraud, money laundering and copyright theft.
Dotcom, born Kim Schmitz, denies any wrongdoing and is free on bail in New Zealand ahead of his extradition hearing.
US intelligence leaker Edward Snowden, in limbo at a Moscow airport, is also seeking to evade US justice after leaking explosive details about a vast US electronic surveillance programme and bugging of European missions.
Germany has reacted with particular alarm to the revelations about the US and British spy programmes, given its history of state surveillance under the Nazis and the communist East German regime.