can't control son's it use

It's not clear what your concerns are.  If you think you are keeping him safe, then he's finding ways around your rules.  

What are your fears?

My concern is 2 fold. Firstly that he is posting without consent and secondly that he is so savvy that I wonder what else he is doing that we are unaware off. 

It is very hard to reason with him and he is renagging any rules. My instinct is to remove his phone and tablet but not really coherent for day to day life. He doesn't accept any responsibility for his actions

We have had a previous instance of spying on his cousin whilst she was changing ando trying to take photos but we caught this on time. The upload on this occasion seems harmless enough but he clearly has no perception of what is and isn't acceptable and worried where it will end up. 

I think you may be turning the internet into something mysterious and exciting for him by the way you're limiting access to it..  Really, I think you need to be very switched on yourself and be showing how to get around safely without compromising his access.

You need to suggest to him about keeping his identitiy secret and not 'giving' information away.  

You need to explain to him about the dangers of the internet and what the risks are and how people are always looking to rip you off, steal your information and get your data.  Make him understand that the internet is there to be used - and I'm not sure I'd be limiting the access - I'd be encouraging him to talk to you openly about what he does and encouraging him to make fake ids.

From the age of 8 I always encouraged my daughter to use the internet freely - as long as she protected herself by creating false identities and using false addresses and telephone numbers (we used legitimate addresses from major museums and their phone numbers for fake ids so any checkers would find a valid address).

We created false Facebook profiles so she could look around and be nosey without leaving her own ID anywhere so she could see what it was all about - and see the bullying going on.

She was all sorts of kids forums where she learned all about not getting into fights on there - because you really don't know who you're dealing with.

She became VERY tech savvy and only started using her real name on the internet very recently - and she's now 20!

I think you may be turning the internet into something mysterious and exciting for him by the way you're limiting access to it..  Really, I think you need to be very switched on yourself and be showing how to get around safely without compromising his access.

You need to suggest to him about keeping his identitiy secret and not 'giving' information away.  

You need to explain to him about the dangers of the internet and what the risks are and how people are always looking to rip you off, steal your information and get your data.  Make him understand that the internet is there to be used - and I'm not sure I'd be limiting the access - I'd be encouraging him to talk to you openly about what he does and encouraging him to make fake ids.

From the age of 8 I always encouraged my daughter to use the internet freely - as long as she protected herself by creating false identities and using false addresses and telephone numbers (we used legitimate addresses from major museums and their phone numbers for fake ids so any checkers would find a valid address).

We created false Facebook profiles so she could look around and be nosey without leaving her own ID anywhere so she could see what it was all about - and see the bullying going on.

She was all sorts of kids forums where she learned all about not getting into fights on there - because you really don't know who you're dealing with.

She became VERY tech savvy and only started using her real name on the internet very recently - and she's now 20!