from what i can understand, the IP is registerred to iburst and as far as i can tell is used for multiple customers either through proxy or through assigning multiple customers to a single IP
the reason why the IP is 'currently downloading a 70826523 AVI file' and also being flagged as a leach bot because of the constant downloads of multiple and seemingly unrelated files constantly being downloaded by that specific IP
http://www.google.co.za/search?q=196.46.71.251
my IP is, i assume, CT specific as it's based, according to IP searching, in the BoKaap area. it's logged as a known spam harvester, leach bot etc...
i've spoken to the call centre intelligencia about this and recieved a well thought mumbled "uuuuh..."
this is often done on company networks in order to save on static IP's, for an ISP to do this just shows cost cutting intention at customer expense by decreasing the number of connections