DS (13) has been having some poor attitude recently and swore at me earlier this week so I confiscated his phone, tablet and PSvita. He had shown better behaviour the rest of the week so I allowed him his phone back today but I said he had to allow me his password first and I wanted to check his phone as his behaviour recently hasn’t been good and I suspect there is maybe a new friend or something going on that he would rather I didn’t know about. He refused and has taken his phone. He became extremely possessive of it and raised his voice to me saying it was his personal business. He won’t give it to me and will probably hide it tonight when he goes to bed so I can’t take it when he is sleeping. I’ve taken the router for the internet so he can’t go online and I don’t think he has any credit or money in his bank account to top up. I told him his behaviour is leading me to believe he is hiding something from me but he denies this. He is probably deleting all incriminating stuff as I post this.
What do I do now?