For example, if I know (or suspect) that a Jew is infringing on someone’s intellectual property (copyright, trademark, patent, etc.), can I report to the person who owns the IP? I don’t know whether or not the IP owner will take action or not, so it may or may not result in a loss of money to Jews.
If I report them to the owners of the IP, am I a moser (whom everyone is required to kill)?
That’s not Mesirah. If the guy is stealing something then it’s not Mesirah to tell the person he is stealing from or the government (so long as the penalty will not be more than Halacha would require).
If someone is a Goniff, you should report them directly to the person he is stealing from, in order to prevent direct and future losses. Besides, that private (non-governmental) individual does not have the power to impact the perpetrator’s life beyond what he possibly deserves Al Pi Halacha. Where it involves government regulations, it is definitely in place to ask a major Posek.
If in this particular case (when someone is stealing) is mesirah has nothing to do with the OP’s question. The question was in general if it is permited to report for a privat entity when its not permited to report to the goverment. I beleive its the same, the lashon of Chaza”l is ???? ???? ????? ??? ???”? (handing over the money of a jew to the gentiles). Of course in this case its not the jews money to begin with. However if its assur to report to the goverment for exemple if they will give an unfare penelty then its also assur to report to non goverment entity’s.