The ones starting with 0x00034253 seem to be BitSpirit. I'm not entirely sure that this is correct but I'm not going to subject myself to Azureus's code long enough to check.
Not all parsable peer IDs start with 8 bytes of printable characters, you know. If you tell people to stop posting the hex ones then you're missing out on the occasional client.
BitTorrent is an open source Internet distribution protocol. Amazon S3's bandwidth rates are inexpensive, but BitTorrent allows developers to further save on bandwidth costs for a popular piece of data by letting users download from Amazon and other users simultaneously. Any publicly available data in Amazon S3 can be downloaded via the BitTorrent protocol, in addition to the default client/server delivery mechanism. Simply add the ?torrent parameter at the end of your GET request in the REST API.