What's a basic "I'm not responsible for anything" legal policy?

I'm beginning to put out lightweight online communities pretty quickly -- about 1 every week! Many of these communities are oriented toward social change, and aim to provide the necessary infrastructures to make big social change and mass movements easy.

So naturally I'm worried about my liability, and also possibly making intelligence agencies interested in me.

...

What's the most watertight and simple "I'm not responsible for anything" policy I can put on my sites as a US citizen?

What are some examples of cases where no matter what policy I state, I am still facing liability just because I wrote some code that provided a community infrastructure, and maybe some users used it to carry out illegal activities?

Is there any way I can definitely deny responsibility, or are there some lines I can't cross? For example, if I created some infrastructure whose instructions for use (written by me) would typically, but not necessarily, involve some illegal acts? (Assuming I never actually mention the illegal part, and the instructions could be used in a legal fashion.)

Do I ever have any responsibility to monitor user content/actions for illegality?

This is a question for a qualified lawyer. All this "internet liability" issue is hard to understand and interpret. It also depends on the location (and it can be very complex! Consider a situation like this: you as provider are U.S. citizen, your data are stored on some server in Germany and some Somalian user is using it for illegal operations... A mess!)

Concerning location, I can tell you that here in Europe, even the judges hesitate how to interpret the involved legislation (often 50+ years old laws about telecommunication or press publishing - completely obsolete nowadays).

So the only advice I can give you is to contact some local lawyer - if possible specialized in IT & internet issues. And the very last thing: the "I'm not responsible for anything" policy DOESN'T EXIST!!! Be sure that you will ALWAYS be responsible in some way. This is just a myth and any such a clause will not protect you in case of law suit! Disclaimer: I am not a lawyer