A scanner indeed...
The ONLY way to stop floods is to eliminate the use of ALL bots... to this i agree
BUT, IF Blizzard was to do so WITHOUT making a GOOD channel / moderation bot of there own for use by Clans as Moderation, Database and Add bots. OR have people submit bots to blizzard to approve them and blizzard add some bit of code that makes them work.
OR (my suggestion)
if a key gets logged on then logged off and then logged on again quickly in a entirely different location (Static IP check) ban the key for a decent amount of days or the Static IP or both. but... you need to tell how long for traded key to wait to log...
even the BEST Flooder only own at most 1,000 working keys and most only have about 50 - 200 working
1 hour per trade time , with 500 keys , 500 proxies , banning speed of 1 proxy every 3 seconds 1200 bans per hour and the flooder would want to keep the flood constant so they would spread out there resources.
for that is about 57 per minute which would require about 4 moderation bots banning at 1000+ bph
so... well it needs some modding but its a thought even though it does not seem to work when i do the math... (use the first idea)