[@Ellri]
Issue I thought that could arise if the Tags and smilies are limited is the continual new messages with someone clicking each name and following up with a sudden 'enter' press. In that case, maybe if a certain number of messages are put up in a certain amount of time, a short time out is issued.

[i]Eg: if 3 messages appear within 10 seconds, a 15 second cool down period is issued[/i]

Now I could be going about this the wrong way and someone else may have a more refined option, but it might restrain those that wanna spam cause they know the more they do it, the less they'll be able to speak.