That is harassment. Different from arguing.
Arguing I wouldn't punish as long as it is done in the proper place. We need to have a little bit of this. When we ask others to look at our RP and they feel strongly about it, there is bound to be a debate. GarenxKat I would argue about. ALL DAY LONG. Same with placing an alignment on Morgana and Kayle. As a matter of fact, I HAVE argued with people about it. I feel better for it. Not cause they listened to me, cause they didn't, but because I learned about their side of it and could better understand their reasoning. I don't totally agree, but I could understand it better.
Harassment (Which I have yet to TRULY see here.....unless you count Unexisted, which I don't) has no place anywhere and deserves the full fury of Riot to crash down upon their accounts.