Otherwise if you don't hold a clearance, I don't think they can do anything to you (however, I am not a lawyer so don't take this as a legal advice etc etc...)
I remember reading people with clearance were not allowed to access wikileaks, but I can remember any follow up "X got fired|trialed because accessing wikileaks". Not that I think it can't happen if we didn't know about it, of course.
Of course it's also a great medium to screw someone over, but that's a whole other thing.
It effectively lets through psychopaths, very good liar or those that know how polygraphs work and presumably practiced passing it.
They are typically used in criminal investigations as a way to make suspects feel uneasy so investigators can pick up visual tells.
The fact that police services can use it to extract confessions is just a nice bonus, and it's really a really cheap alternative to conducting a complete and thorough investigation. Police policy has for a long time favored confessions over investigations.
It is, however, still a part of getting or maintaining clearance. A friend of mine wound up changing jobs simply because he failed the polygraph twice and didn't want to bother going in for a third.
Utter bollocks, them.
Also, I know it's technically kind of bad form but if one wanted to run Tails easily you can use VirtualBox (https://www.virtualbox.org/) to easily fire up a throwaway instance of Tails quickly and easily.
http://leaksource.wordpress.com/2013/04/08/wikileaks-plusd-p...
So it is legal
If the materials were still classified-but-leaked then I won't go near it until it is declassified. But I can't tell from this side of the window what's going on.
Also, elements of the intelligence community have made statements that suggest that applicants to some government positions could be refused if they tweet or say anything about Wikileaks. [1]
1. http://dailycaller.com/2010/12/09/schools-warn-students-not-...
http://www.aclu.org/blog/national-security-free-speech/gover...
And if you're working for the US government then you had better play along or you might end up causing your career harm.
Common sense is at odds with the law here (and in many other places as well), so 'what you know' and what some judge will decide may very well be in contradiction with each other.