This is not contribution to the HP issues at all - as promised I won't comment on that to keep the board peaceful -, but the answer why people do not sue or give up over IP theft.
1, You need to have around $30,000-$50,000 in advance to start such a case. Remember you worked on the project full time, you don't have that sort of money at the time.
2, You've been working on your project on minimal income, loans, help of friends whatever. Basically you spent money on the project and was off regular income - that most people asking such things take granted.
3, You must produce your life expenses. Even if you somehow manage the IP case, it will just cost more over time, which you won't be able to finance.
4, Your business model was based upon incomes that due to you. If that does not happen you are facing much more serious problems, than to care to sue the bastard screwing over you.
5, You find a real job instead and slowly pay back your debts: the money you spent on developing the project...
6, You don't look back after a while: any minute spent on something that just costs money is one more minute wasted.
7, It is typical the these screwing over issues "normally" happen if you do not have a legal representative in the offenders country. Even phonebills will be prohibiting after a while, but different legal systems, proceedings, conditions all make sure the bastard can get away with it.
I am positive both Metin and I already pointed out the logic how it works and why several times, and there are few people - maybe on this board as well - who could contribute to these clauses as well.
Basically: only sell stuff to companies legally responsible fully in your countries, or make sure you team up with people who can represent you in your partners' country. You can avoid all these shit things happening as the "tempatation factor" of ripping you off will converge to zero if your partner sees he can be looked after properly.
Any other way you will be ripped off.