Rationality is not equivalent to empiricism, as you seem to be implying.
>There is precisely as much evidence that the NSA is blackmailing presidential candidates as there is evidence that there is a camera in my underwear drawer or that chemtrails exist.
But the plausibility of the two are incomparable. Given what we know about human nature and the information available, and the abuses already made public, it is a legitimate fear. This combined with the immense gravity of such abuses, a rational consideration of the facts indicates that we take proactive measures to prevent it.
You say chemtrails are implausible? We already know that the TLA's have experimented with mind control agents, ala MKULTRA (though under different circumstances) and probably other still-secret programs, so using the rubric you just described, chemtrails are also a legitimate fear.
When it comes to chemtrails, a whole string of highly improbable assumptions are necessary for it to be true. The probability of these two cases are not comparable.
http://en.wikipedia.org/wiki/Cloud_seeding
The only reason the US doesn't use weather modification in war is because of signed international treaties.
And if you string together conspiracies without a shred of evidence to support them, you are by definition making shit up whole cloth. This puts you in the same irrational company as Alex Jones, Art Bell, etc , etc.
The existence of bad actors absolutely does not mean that we abandon all critical thinking and logic and rationality. There is precisely as much evidence that the NSA is blackmailing presidential candidates as there is evidence that there is a camera in my underwear drawer or that chemtrails exist.