How to avoid being sued for your software? [closed]

Question

I have a written a small app as a research project that uses open source libraries. It can do packet sniffing, network scanning and man in the middle attacks on wifi and lan.

This software is intended to be used for security auditing.

But users can also use it to circumvent the MAC filtering of their ISP and get free internet.

The case seems similar to that of uTorrent. uTorrent can be used legally, but almost everyone uses it for illegal downloading.

If users download my software and use it like that, can the ISP sue me as the author of the software? What should I put into the Terms and Conditions to avoid being sued for misuse of my software?

EDIT
I'm from Eastern Europe, but live in the UK. In which country should I ask a lawyer? People can download my software globally.