but how about a client-sided version of the ID mapping project?
Normally this would be impossible because in order to submit a player, you have to know their IP address, so the data can be verified. But a workaround is to validate data via peer agreement: 10-20 players submit data and if most of them agree, the data is not fake.
Hammer, even if it may only help a little; I suggest hosting images through imgur or cubeupload to put less strain on your network when under load or attack.
My network, even though it has 25 Mbps upload, is usually never filled to even 50%.