People shouldn't have to be "warned" about this. It's called spam for a reason. Pushing the button once should get your point across. When I hopped into PVP to get Goten it would irk the crap out of me when I saw:
Attacking healer ×6
Not enough that I would report anyone over it but I'm not surprised people are taking steps to stop the spamming of these chat commands. If anything, when someone spammed like this I noticed more people would go out of their way to not follow the spammers directions.