Congrats on passing the SOL. Your story is very similar to mine. The one difference is a point I am going to respectfully disagree on.
I think it is worth it to respond one time with a fair offer to settle and a request for proof of ownership. It only costs a little education time and a stamp (or a nominal legal fee if you want to get Oscar to make sure it is done right). Of course it will likely be rejected. But in the [probably unlikely in most cases] event that you land in court it might go a long way in showing you took this seriously and tried to resolve it in good faith.
And this is where our opinions begin to merge again. Any further back and forth and arguing is probably just a waste of time and energy in my opinion.
Congrats again.
Reasonable minds can, of course, differ on this point. I don't think it matters much in any case. With that being said, here was my reasoning for not responding at all.
1. I don't think whether you take the demand seriously or try to resolve it in good faith matters at all in a courtroom setting. In most circumstances in federal court, the efforts of the parties to resolve a legal dispute are not even admissible, under Federal Rule of Evidence 408. Getty would not try to introduce your settlement letter (unless you admitted to infringement), and there would be no purpose for you to offer it in your case. The issues in a copyright trial (including whether Getty held a valid copyright, whether you infringed that copyright, whether that infringement was willful, and what the damages should be) have little to nothing to do with whether you offered to settle the case. I think it's nlikely that your settlement letter ever makes it into evidence at trial, and even if it does, it is of minimal relevance.
2. However, if you write Getty a letter, it demonstrates to them that you are taking this seriously. That just shows them that you're "a live one"-- you're concerned enough that you've started researching the issue, bought a stamp, written a letter, and offered to pay them. That's their bread and butter. I would imagine that the majority of people that wind up paying Getty off are people who wrote a letter just like that. While I have no idea what their internal processes are, it would not surprise me if the people who get more letters, more emails, and contacted by debt collectors are the people who have indicated that they are nervous or taking this seriously.
3. On the other hand, if you never respond at all, Getty has no idea whether they even have the right address for you. Maybe the business is defunct, maybe the owner has retired or died, or maybe you put down a fake address when you registered your website with GoDaddy. The less they hear from you, the less incentive they have to try and pressure you. They'll just put your address into their automated mailer serice, send you a form letter every three months, and do nothing further.
4. Finally, there's no reason to take this seriously in most cases. If somebody sends me a letter telling me that I owe them hundreds of dollars for resurfacing my driveway, but provide no proof that they actually resurfaced my driveway, I'm not about to write them a check. Same thing here. Absent any proof that they own the copyright they accuse your of infringing, it's no different than a Nigerian scam email asking you for money. File it away, ignore it, and move on with your life.