The context is that the author is speculating whether Snowden still has access to the NSA system via fake accounts, backdoor codes, etc.
Moreover, he could wage a one man counter blackmail operation. Say for instance Ed Snowden knew that the NSA had dirt on Obama from its earlier monitoring of his days as a Senator that it was presently using to pull his strings,[bold] or say that he knew that the NSA was keeping a certain South Carolina Senator's homosexuality under wraps in exchange for subservience, he could release that info and neuter the NSA's blackmail grip. He could reveal Obama as a complete shell and puppet of Gen. Alexander's NSA.[/bold] He could go global, as he seems to be doing and reveal how the NSA blackmails certain Prime Ministers, or how Israel is pulling the strings on its puppets in DC like Peter King, McCain etc. He could show just what media outlets are compromised (OK, we know it's all of them but... Snowden could get very specific and show that a certain bombastic FoxNews blowhard has a penchant for underage girls or something.