Account Hackers

I'm really sorry to post this thread .I didn't know where else to post it . Its really annoying that people friend you and send you links telling you they offer free skins and then when you open it you find the same league of legends login screen . I have been sent one today but I didn't login because I have been warned many times but what about the other people? is there anyway that this could be stopped ? I have a screenshot if you would wish to have a look at the conversation. Sorry If I posted in the wrong area. Thanks for reading