I believe, though, that under US law if you don't act to protect your copyright or trademark then it can lapse. So some companies will sue for what they see as copyright or trademark infringement even if the infringer is not doing so for profit - just in case, in a future court case, the court rules that the company has a history of not defending.
I may be wrong about this, would love to know for sure if there are any legally knowledgeable members around.
Anyway, surely even if someone makes no money they can still be sued for damages and in addition have punitive damages applied?
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Also, if found guilty of trademark/copyright/IP infringement, mightn't the defendant be liable for the injured party's court costs? Those can be staggering.