I think I can quite categorically say I've never done anything at a football match to risk harming another human being, whether it be a fan, official or player. (well, apart from the odd occassional silent but violent). I admire your youthful exuberance at times but don't even think about trying to defend throwing coins.
How would you feel if someone threw a coin at you ? Maybe that coin cut you, how would you feel ? Maybe that coin blinded you, how would you feel ?
They've obviously caught no one yet but announce it over the tannoy, on the website, put it in the programme and say if caught you're getting a lifetime ban and there's no excuse then is there. To be honest, what sort of a moron throws coins or missiles or lets the culprit off or even justifies something like that. Just my opinion like.