Thank you once again Salem and also Stylish for your excellent replies.

Salem, I'm going to write down the steps you suggest to see if there are any shares on my pc, this might be very interesting.

I actually laughed out loud at the 'morse code' nudges, it's a brilliant idea!! Imagine the embarrassment for my son if he is in fact watching the conversations. You can actually pick your own nudge sound but I would imagine that if my son doesn't have this setting on his pc the altered sound would still sound as the original one. I'm slightly disappointed that my daughter didn't confront him at the time and ask to see his conversation box showing the nudges that were received by him. She said that at the time disbelief and shock stopped her from asking him. She too laughed at the thought of the morse code nudge catching him out .

Stylish, I do think you're right about the emails. He did seem genuinely mystified about it and added that he had no idea the program downloaded them to the hard drive. He's not a good liar and I believed him at the time.

I think I may confront him as you say. He's not aggressive or nasty, just extremely nosey, lol. I want to try the steps that Salem describes first, partly to have more ammunition and partly to avoid accusing if I'm wrong.

I think his nudges are pretty strong evidence too though but although we intend to try the morse code nudges, I feel he will have been mortified at the time those 3 came through and will have now disabled this particular sound. So confrontation may be the only way.

I'm actually tempted to ask him to search for the mentioned sniffer programs while I watch. Although he's 18 and a bit of a self taught computer whizz, he is still very home dependant and quite childish and will probably comply without too much argument.

I'm going to look a little into the proxy thing you mention too.

Thank you so much once again for taking the time to help me it really is sincerely appreciated .