The purported hack of the National Security Agency sends a message that the United States can be held accountable if it meddles in the affairs of other countries, Edward Snowden said on Tuesday, particularly if it it’s hacked any elections.

“This leak is likely a warning that someone can prove US responsibility for any attacks that originated from this malware server,” the former NSA contractor said in one of a series of messages on Twitter. “That could have significant foreign policy consequences. Particularly if any of those operations targeted US allies. Particularly if any of those operations targeted elections.”