http://na.leagueoflegends.com/en/legal/termsofuse#virtual-goods
4.3. Do I “own” the Virtual Goods I unlock? (No. What you “unlock” is not the virtual good itself, but rather, a qualified right to access it in the Game.)
You have no ownership or other property interest in any of the Virtual Goods you unlock, regardless of whether you acquired access to those Virtual Goods using Riot Points, Influence Points or Hextech Crafting. Virtual Goods have no monetary value. You can’t redeem them for cash. You can’t obtain any refunds for purchasing Riot Points or Virtual Goods, except as expressly permitted by us. You can find our current content refund policy here.
We have the right to delete, alter, move, remove, or transfer any and all Game Content—including Virtual Goods—in whole or in part, at any time and for any reason or no reason, with or without notice to you, and with no liability of any kind to you. We don’t provide or guarantee, and expressly disclaim, any value, cash or otherwise, attributed to any data residing on servers we operate or control, including any Game Content attributed to your account. The sale or transfer of your right to access certain Virtual Goods, Influence Points, Riot Points or Hextech Items may only be conducted via services approved of or provided by us, if any.
4.4. Once again: I don’t own these Virtual Goods? (“No!” shouted all the lawyers.)
NOTWITHSTANDING ANYTHING TO THE CONTRARY HEREIN, YOU ACKNOWLEDGE AND AGREE THAT YOU SHALL HAVE NO OWNERSHIP OR OTHER PROPERTY INTEREST IN YOUR ACCOUNT, AND THAT ALL RIGHTS IN AND TO YOUR ACCOUNT ARE AND SHALL FOREVER BE OWNED BY AND INURE TO THE BENEFIT OF RIOT GAMES. YOU FURTHER ACKNOWLEDGE AND AGREE THAT YOU HAVE NO CLAIM, RIGHT, TITLE, OWNERSHIP, OR OTHER PROPRIETARY INTEREST IN THE GAME CONTENT THAT YOU UNLOCK OR ACCUMULATE, REGARDLESS OF ANY CONSIDERATION OFFERED OR PAID IN EXCHANGE FOR RIOT POINTS OR VIRTUAL GOODS. FURTHERMORE, RIOT GAMES SHALL NOT BE LIABLE IN ANY MANNER FOR THE DESTRUCTION, DELETION, MODIFICATION, IMPAIRMENT, HACKING, OR ANY OTHER DAMAGE OR LOSS OF ANY KIND CAUSED TO THE GAME CONTENT, VIRTUAL GOODS OR RIOT POINTS, INCLUDING THE DELETION OF GAME CONTENT, VIRTUAL GOODS OR RIOT POINTS UPON THE TERMINATION OR EXPIRATION OF YOUR ACCOUNT.
You don't own any content on your account. Revoking that content is within Riot's rights. This is from the Terms of Use you agreed to when you created your account, and that you agree to again every time there's a patch.