Re: Mahou Shoujo Elina
It blocks a massive amount of connections that will look into what you have been doing. So if you ISP is looking at your line, all they're going to see is that you have X amount of bytes coming in. They won't be able to tell if it is a torrent or if you're just streaming something from netflix.
I start that up every time I torrent now days for security's sake.
Well, not really. Peerblock will block the RIAA/MPAA from using another torrent peer to see if you're downloading the file. This is basically a firewall with a special blacklist - it'll prevent you from connecting to certain computers known to be performing that particular activity. The lists are maintained by Peerblock, and will only be updated as often as Peerblock is updated as a result. Likely, any blacklist they have is already woefully out of date, as the MPAA/RIAA were known a couple years ago to change IPs frequently to avoid this issue.
What Peerblock won't do is prevent your ISP from seeing what those packets of data contain; they are almost always not encrypted, and can easily be recognized when using deep packet inspection - which is the way every ISP that uses traffic shaping does it nowadays.
A great analogy to understand this is to postcards. An unencrypted packet is really just like a postcard, since there is nothing to prevent someone from seeing the text you write on it. Imagine you have a dedicated pipe for your postcards to be directly delivered to your house from the post office.
The organization providing that pipe can either see what you do with your postcards by sending you special postcards every once in a while to see what you do with them, or they can automatically scan them all at the central station, know who is sending it (since it has a return address), and see who you're sending it to, and what it says. The scanning option is far easier, can be implemented on a much larger scale, and is the way an ISP handles torrent traffic.
Peerblock would prevent the first way, since it'd stop you receiving mail from the pipe's provider (if the list was up to date), but not the second way, since you still have unencrypted mail coming and going through the pipe provider.
The way to stop the second scenario from happening is using encrypted connections. Encryption changes the data so it's unrecognizable. One of the easiest ways to explain encryption is the Caesar Cipher. Julius Caesar used this to communicate with his generals. Wikipedia has a good image for it, but it's simple enough. Take any letter, and shift it so many off from the original alphabet. Example:
ABCDE....
becomes
EFGHI....
Modern encryption is way better, but the idea is the same - make the message gibberish to someone who doesn't know the code to decrypt it. When you do this, deep packet inspection fails, and your traffic cannot be read by the party between you and the other person you're sending/receiving messages from. Unfortunately, most people don't really use encryption on torrent traffic, so you're basically SOL on throttling.