I am kinda of saying tell your mother, or have a talk with him. If you do decide to talk to your mom, then just tell her that a 11 year old does need to be supervise while on the internet. There are somethings that they can go into, that would absolutely not be good for him. He is 11, much too young for some of the things that pop up on the internet. I think your mother need to know, so that she may at least try to see that he does the right thing.

You love your brother and you are going to have to do what you think is right for you and him.

Willie