Yes, it is illegal to download above 6.2 kb/sec on a dial-up modem, it's difficult to track though.
Spyder, i've explained why it's possible to get some insane speeds on downloads. There are limiters built into the modem to prevent connections above 53k....sometimes they fail during a connection and download speeds temporarily increase. I've had it happen with getright for nearly an hour downloading a 20kb/sec. I even verified it in timing with windows explorer and checking the filesizes.