I've recently discovered a seller on eBay who is selling CDs with my (trialware) software on it. The seller is clearly trying to pass the software off as his own; he's copied all the verbiage from my software's website, except its actual name.

This seller also sells a whole bunch of other CDs with free software for which he's misrepresenting authorship. For example, this listing contains screen shots that are obviously of the free program InfraRecorder. However, the name InfraRecorder or its authors aren't mentioned anywhere.

Before I splurge on official legal assistance, does the community have any recommendations or past experiences with these kinds of matters? What's the best way to proceed, and at the very least, have the eBay listings taken down? Is it possible to reclaim the earnings from the sales of these CDs (not just for me, but for the other authors of the free software that this person is selling)?

I realize that GPL'd software doesn't have any restrictions on "selling" the software, but this person has gone to great lengths to obfuscate the software's authorship, which is surely a violation of the license. (My software is not GPL; it's a custom license, and it does not permit redistribution of any kind without permission)