What should I do after receiving a letter for copyright infringement? How?

Respond to the letter asking for detailed information regarding what was allegedly downloaded and when. Also ask who specifically owns the copyright and what gives this company the right to make this claim. In short, first find out if this is a legitimate complaint or if it's just some copyright troll trying to bilk you out of money. Second, contact your IP provider to see if it has any information about the situation (did it get a request from this company for your IP address, etc.) Third, determine for sure that there is absolutely no chance that anyone was in your house or had access to your IP address on the date that the material was allegedly downloaded. Check if you have wi-fi to see if someone stole access to the Internet and your IP address somehow. If the company can prove that the movie was delivered to your IP address, you may have to pay for it.

I wrote a paper on this subject back in 2012 - You Might Be a Copyright Pirate. Here is an excerpt: Here is a common fact pattern in such matters: A subpoena arrives in the mail regarding a copyright lawsuit filed against a number of "Doe" (i.e., unnamed) defendants in a local federal court. Accompanying the subpoena is a lawyer letter requesting from $3000 to $4000 to settle the matter without further action. Why did you get this letter? Simple, your IP address was identified as a participant in a BitTorrent download of a copyright protected movie, often an adult film. Can you fight this? Yes, but may cost more than the settlement offer. Would you want to fight this? Maybe not, especially if an embarrassment factor is to be considered. Do you have security on your internet access point? Do you have a teenage son in the house? Check out the facts before you respond to the letter.