[OFF TOPIC] Finding an IP from a Mac Address

[Raphaël HALIMI <RaphaelH@Cybercable.Fr>]

Hello. This question has nothing to do with Debian, but I ask here because I
really need a quick answer, so I try everywhere I can...

Yesterday, again, somebody downloaded 60 Mb from my machine. It's the third
time this month. I wouldn't mind, but I have a cable connection and my ISP
allows me only 125 Mb of upload... And every Mb above this limit is to be paid,
3 Francs, which is about 0.5 $ :-(

All I have is a Mac address (aka a hardware address), from the log produced
by iptraf: 08003e06045b.

How can I find which computer this address belongs to ?

Thanks for any help.

-- 
Raphaël HALIMI

Bash Scripts !! http://www.linux-france.org/prj/bash-scripts