Skin Replacement Questions / Clarification

[Scooby]

Hi, I have a few questions, maybe someone out there can help me with.

I have DM server and Im told people are joining the server with modded/replaced player skins,

(really small skins, half the size of normal) and im told these players cant be killed very easily since when u aim at their head,

the just bullets go right over the top of them and they only take damage if u shoot them below the waist.

just lately everyone is accusing everyone of cheating.

so my questions are:

1) is there any way to detect who these people are?

2) is there any way to stop these people joining?

If u have any ideas/suggestions please let me know. thanks.

[Tren]

onPlayerModInfo ( + resendPlayerModInfo ) can detect mods.

[Scooby]

ahh sweet, thanks... i can do something about it now