You can't really make NSA knock-knock jokes since knock-knock jokes have the premise that the visitor tells you they're there and lets you ask questions.
Madness string 33189
More than half of adults in the US have a reading comprehension at or below the level of a child in grade six, and more than 20% are functionally illiterate. It's not that different in other countries either. Once you know that, both the Internet and the state of political affairs make a lot more sense.