Not only should you accept that the feds would monitor a site such as this, but also that all harm minimisation sites would have at some time been and still could be checked out.
If you are wondering about your site, get a stats checker and see what the origins of the visitors are. Very suspicious is anything from "US military", where the CIA operates such internet activities from.
How do I know this? It happened to us. No consequences though, and on checking up with a local government spokesperson, he said it is normal for the CIA to check any group operating anywhere as intended harm minimisation.
When you think about it, if they can record selected mobile calls, via artificial intelligence monitoring the words used, it would be very easy to "keyword notify" with postings.
Just don't use the words drugs, bombs, prime minister, USA, lots of money, and guns in the same sentence. Oops
Mind you, as has been said, what can they really obtain from here that they could act on? - very little that would be risky to anyones liberty. We have our dedicated moderators to thank for that.
But I bet they do have good plans for building a bulberator!!
phase_dancer