bravo to the big brother who is soo protective of his lill sister ..12 is indeed very young age to be exposed to evil sick ppl lurking to prey on young girls. But no matter how much you try to control you sister, if she has a will to get out of way to use technology to connect with other ppl. You need to nip the issue in the bud by getting to know your sister and understanding her motivation to do all this. Is she craving for attention/ acceptance from othes which she is not gettng from ppl she expects? I understand your concern being the elder siblings i have tried so many tactics to spy on my younger sibling but insted inflicted more stress and ruined my relationship with them. Hence empower tham to make better decisions for themselves. Teach her how to identify good influence from bad ones....make her watch Oprah/ Tyra and other educational shows where the victims of internet crime ahve spoken out to save other ppl from going through the same fate. Definately continue the survaillence but also help her grow up safely ....