There are so many spurious terms of agreement that you two have with your ISP, that if he proves you were at a certain location and posted a certain thing, that may or may not be enough to get your account terminated at the ISP.
I know this because I have seen grown babies (manchilds) do this to one another when they get a little too stupid for words. Then they turn to the FBI to have each other investigated like idiots.
You'd probably think that people in high authority in the US government and the Armed Forces are different than you average folk. Lets just say, the only difference is their ability to use English properly. Some of the nasty ones even turned to department heads at AFOSI and DIA (and/or the FBI) to have them frivolously investigated.
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Point being, watch out. (to both of you)
You are probably thinking of context sensitive crawlers and flagging. In which case you'd probably have to write it out in a different language if you want to draw any attention.
If you threaten to blow up the white house (or harm the president), the FBI is obligated to investigate such occurrences. (Yes, they actually send someone...well if you report it at least.)
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http://www.theguardian.com/world/2013/jul/31/nsa-top-secret-program-online-data
Thats just one tool that is recently become public. The tool allows someone to type in a web address such as: www.butterflylabs.com and it will give an analyst access to the IP's that have visited that site.
Or you could type in your IP and a few keywords and bring up your online browsing history.
Google History: https://accounts.google.com/Login?service=hist
You can wipe your history off the public servers but retention means it is available for a long, long time.