@theymos,
are you obliged to give them these 'data' or not?
Awesome.

Use PGP if you want privacy.

You are right, I can't imagine someone read a pgp encrypted message and he doesn't know what the hell is write in that message (because he doesn't have the key for decrypt it

).
Subpoena is a court order, so yes he has to respond (either consent or fight it in court) or he can be jailed.
And yes you should always use PGP or something else for sensitive communications.
I hope they enjoy reading my pm's to Inaba warning him to stop trolling and derailing threads, and him whining about someone else starting it.
1. Bad form badbear shouldn't talk about Inaba behind his back.
2. The issue for the forum is going to be persistent given the loads of scams present. This won't be the last time you are going to get a subpoena. Might want to start collating all the other major scams you can. Good luck.