Edward Snowden, NSA whistleblower

I recently heard Edward Snowden may be dead. He tweeted a series of 64 random letters and numbers that people are saying could theoretically be some type of "dead man's switch" scheduled to go off if Snowden is kidnapped or killed. I'm sure there are other possibilities on what it could be but until there is proof he's alright I can't help but wonder/consider the possibilities.

Does anyone have any other theories/thoughts?

Very curious to hear people's thoughts!

Peace and Love,
Miki