I once had a Beta leaked from a testing group. It had a software crash reporting feature built in, so it emailed problem reports when it crashed. It was a Beta, and the Beta participants were told - no foul play. We found out about the leakage when Beta reports came in from ten times as many machines as we'd offered Beta copies, and from countries that weren't included in the Beta test. What could we do? Nothing. Without an identifiable component (e.g. steganographic printing of each distributed copy and matching that to the discovered versions or having the crash emails include a key) - no police force would take action.
If your software is related to finance. and exported from the US, then the US Secret Service may be interested. They take interest in anything that devalues the US Dollar. Again, without any kind of tracking and tracing, you're roadkill.
We ended up realising that we would probably support a community of users between five and ten times larger than we had sold to. Price reductions made a small difference in the ratio. A very few of the "extra" users became buying users, but it wasn't a good lead generation mechanism.
Consider making your product into a legit ShareWare product. Free distribution with nagware or feature limitation pending an unlock. Then the BitTorrent distributors become a friend rather than an enemy.
Cheers, JeremyC.