So, I got an notice from my ISP for downloading torrent

You can always be traced if an ISP looks hard enough for you.

Like JawzForLife asked 'did you get "caught" because of the amount you downloaded, or because of specific files you downloaded?'

Who were the isp?

The ISP could probably care less if you pirate. But they have an obligation to warn you, if for no other reason than it covers their own butt.

Here's a tip, don't download pirated movies from bittorrent.

It's not the ISP's malice that is behind this, a company in this copyright breach tracking business, like BayTSP, gets hold of your IP (they can do that simply by using a torrent client like you and seeing the whole peerlist) - they issue a takedown notice and the ISP is obliged to contact you and deliver the notice.

In this particular case I would advise you to do as the notice says - remove the file from your computer, and do stop using that tracker site.

Does anyone know how to determine for a FACT whether or not and for how long any particular ISP may retain logs??

I see all types of speculation online about this--but no method or definite answer.

Is the only answer to know and ask an insider at the ISP?

Many people think their ISP doesn't retain logs, but they apparently take it on faith with no evidence.

I don't see why it would ever be in an ISP's interest to keep more than the absolute bare minimum of log data--I'd think doing so would only open the door to legal issues and possible liability.

How would they bill you if they didn't keep a log?

You don't have anonimity when you are using torrent, you must simply accept that as fact. Now, if that was a private tracker, I'd stop using it, the likes of BayTSP got inside. If it was an open, public one - well, you are almost asking for it. Do not download fresh releases from open trackers.

Teerex:

I don't use torrents at all. I was referring to instances in which a person pays a flat rate per month, whether you download nothing or 10 terabytes.

I realize logs are kept by default.

The question is how detailed are the logs and whether they are purged after say a day, a week, a month, a year, or decade?

I apologize, I mixed you up with the OP.

I don't know how long they keep logs, but it is surely longer than a month. I can view my IP's from almost a year ago in my ISP's user page. I suppose they couldn't show me these if they didn't keep them somewhere.

A year minimum would be my guess, so, there's plenty of time..

Teerex:

What is your opinion on the detail level of the logs?

Does the log say only that I connected to a certain application or service?

Does the log say only that I was connected for 30 minutes?

Does the log say only that I was connected for 30 minutes and downloaded something?

Does the log say only that I was connected for 30 minutes and downloaded filename y3iee34?

Does the log identify the contents of y3iee34?

Does the log say that my download was successful?

Etcetera, etcetera.

You get my point, I am sure.

I have never heard of a way to answer these questions for any particular ISP.

The log of any ISP shows the start of your connection and the IP assigned to you, and the end of that connection and the IP lease, and the amount of data downloaded and uploaded during that time.

To anyone like BayTSP this is all they need. You are misunderstanding the whole point - it is not the business of an ISP to know what exactly you were doing while connected, what you have on your computer and so on - they don't need it and they do not do it. But when a government or a piracy prevention company suspect that a computer on a particular IP was used for unlawful activities during that time based on some proof, the ISP will provide them with the information about the actual user using that IP at that time.

Here is the BayTSP page - read it, they explain what they do in very understandable language.