Originally Posted by FromScratchSF
Heck, someone can easily just hack into your Wifi or internet connection and use your internet, downloading whatever illegal stuff they want.
If you were to challenge the copyright notice (which would potentially require spending a ton of money on a lawyer) that might be a defense, since it is indeed trivial to use someone else's wireless network if it has not been properly secured. Another defense could be that your computer was compromised by malware and had been downloading and/or uploading copyrighted items without your knowledge, which is again very common.
FYI there's no need to be paranoid about your IP address. Most residential internet users are behind a proxy (a server that stands between your computer and the internet), and while it is possible to modify internet communication headers so someone else appears to be communicating from your computer, this involves significantly more effort than stealing wireless service or installing malware. You don't need to worry about this type of attack unless you are a high value target, in which case you should retain the services of an information security professional (not a computer programmer).
It would be much easier to just find out what the infringement was, that way you would know for sure if you or someone in your family were responsible.
IF it was Disney or another copyright holder that caught wind of you making a character cake, you would not be hearing about it from your ISP. You'd be getting a C&D letter direct from the attorneys representing those companies.
Correct, but if you posted copyrighted Disney images you would indeed hear about it through your ISP via a DMCA takedown notice. The copyright owner may also have no other way to contact you except through your ISP if there is no contact information available.