Internet Safety for my Autistic 11 year old Son

My son is a high functioning young lad who has problems with social skills.

He is playing more and more online and wants to make 'online friends',  I have spoken to him about safety and what he should and shouldn't do online.

The problem is he sees all communication from all people online as a friendship,  He does not seem to be able to differentiate between online friends and real life friends.

Can anyone offer any help or advice on how to get my son to understand the internet dangers.

All help will be much appreciated.