Apparently he had already been denied a work visa without explanation last year by the US consulate in Munich. However, that decision was apparently later reversed after protests from Washington University in St. Louis. Since that must have been before the Snowden leaks and NSA protests, I'd say it doubtful if those are really connected to his more recent refusal of entry.
Edit: To be clear, I am not suggesting that his refusal was not politically motivated. But the original article suggests (or rather quotes author Juli Zeh on suggesting) a direct connection to the NSA protests and their petition against NSA surveillance.
Apparently he had already been denied a work visa without explanation last year by the US consulate in Munich. However, that decision was apparently later reversed after protests from Washington University in St. Louis. Since that must have been before the Snowden leaks and NSA protests, I'd say it doubtful if those are really connected to his more recent refusal of entry.
Edit: To be clear, I am not suggesting that his refusal was not politically motivated. But the original article suggests (or rather quotes author Juli Zeh on suggesting) a direct connection to the NSA protests and their petition against NSA surveillance.