Run it by your lawyers, but I suspect it's just a case of stupid people will be parted with their money and you can't stop them. They're not actually selling your software, they're selling their time as an assistent.
Here's an interesting idea...set up your own ebay listing with for $1 for instructions on how to upgrade their FLIR. Make sure you use titles that'll compete with the scammers in searches. Emphasize the software and upgrade are already free and all you're selling is a copy of the manufacturers website instructions. You probably won't make many sales, but you may save them a lot of money!
Once again, run that by your lawyers and your marketing dept.