As far as I know, they just "asked" them not to. Voluntarily. Have they prosecuted or arrested anyone for doing so?
Whether or not somebody has been prosecuted for it is as far as I know unknown as of yet, but a google search will show you many of the news about the military censor of WikiLeaks, amongst which is this.
A memo from the US Marines says this:USMC Personnel (Marines/Civilians/Contractors) are hereby cautioned and directed to NOT access the WIKILEAKS website from a personally owned, publically owned or US Government computer system.
By willingly accessing the WIKILEAKS website for the purpose of viewing the posted classified material - these actions constitute the unauthorized processing, disclosure, viewing, and downloading of classified information onto an UNAUTHORIZED computer system not approved to store classified information. Meaning they have WILLINGLY committed a SECURITY VIOLATION.
Obviously committing a security violation as an employee of the US Marines is, well, not a laughing matter.
Which
You might find more info here.
Yes, governments can, have always, and always will try to control anything and everything and suppress citizen rights. What I am saying is that in the case of Wikileaks, I don't think they have succeeded yet, whereas the statement "censoring websites from the entire world" suggests they have.
In fact I have, as a non-US citizen living outside of the US, have seen one of the results of this censor when trying to access one of the censored sites, getting a warning page with a FBI DVD-like warning. The problem with censoring the domain name itself is that the website can be hosted outside of the US, and yet they'd have power to censor it.
"Personally I think anyone who spells their nick with numbers in an effort to look 'leet' deserves to have their computer confiscated"
This.
Today is a good day for information-gathering. Read someone else's mail file.