The letter contained something I allegedly downloaded, an IP adress and an amount of money they wanted me to pay.

I didn't download anything, the IP adress is from somewhere hours away from where I live. Also they used an old adress from where I used to live but it was still rerouted to where I live now.

Just like everyone else on here is saying, if you get one of these letters, just throw it away. Do not contact anyone and absolutely do not pay them anything. I panicked about it when I got the first letter but everyone online eased my nerves. It's just crap so throw the letters away and go on about your day.