After a quick review of your posting history, it doesn't take much of a imagination to guess what sort of behavior likely got you banned.
From yesterday:
http://boards.na.leagueoflegends.com/en/c/gameplay-balance/9EQNx1Lk-nerf-ziggs-and-lee
{quoted}
ziggs Q base dmg lvl 1 (120) since it deals over 100 dmg with 30 ap on me with 40 mr on lvl 1. lee sin too. easiest champ ever is lee sin. Q R dead. i just went free kills right now in ranked because you riot makes me lag whenever they are near me and btw i still wont play vs noob champs without skills. exactly all the mages and ad fighters are non skilled champ who deals tons of dmg. this lee had 1 kill 70 ad he did one Q when i had full hp and killed me. **THATS NOT BALANCED NERF HIM AND ZIGGS OR I WILL CONTINUE GIVE FREE KILLS MID YOU WHORE
**
From 9 days ago:
http://boards.na.leagueoflegends.com/en/c/gameplay-balance/zR4Nh76n-stop-nerfing-my-acc
{quoted}
** im in a game right now giving free kills. i will continue this behaviour until i get to play vs balanced champs like zed or i will ruin games like you ruined mine riot**. i wanna play vs challenger players who play normal champs that require skills like kata for example. and another thing in my 10 inranking games i lost 6 because of bad teams and bullshit champs and played supp 4 games and won and yet you place me in silver 5 and says i got mmr like an silver 2 player with 50 LP. while on my main acc that got permabanned i got placed in bronze 5 for winning 8/10 games and the other 2 loses i still got really good scores. your logic soooooo faaaar awaaay from this world and placed in pluto seriously