if I was a fed in the USA, I would specifically check all drugs forums for the use of the word “swim”,
assuming the discussion wasn’t about taking amfet and steroids so they could win the 400 metres freestyle at the next Olympics (an offence in itself anyway), it would be safe to assume that person is the individual commiting an offence with “something to hide” – even if that post couldn’t be used in evidence it could be used as a way to justify using other surveillance methods on the target.
if you are unfortunate to live in a country where the authorities don’t tolerate you discussing drugs online, the only solution is to STFU until you can emigrate to a more tolerant one (its going to be the sort of country what monitors and censors all telecoms traffic anyway).
there are reasons why although this site is viewed worldwide you rarely see blatant posts about drugs from certain countries..
and of course admitting to any form of major crime on any internet platform is just fucking suicidal. No amount of proxy servers, encryption or anything else is going to stop “them” tracking you down eventually.
the control of the internet is in the hands of companies who depend on governments for other business (particularly lucrative fixed telecoms and wireless comms contracts) and they do anything a government wants if their revenue stream depends on it.
