I would be very wary of clicking on these popups. I did once out of curiosity (not that I intended to ever phone it or commit myself to anything) and thought nothing more of it - until I got my phone bill in and had racked up over �69 worth of calls when I had been connected to a sex dialler. I was on the old dial up at the time and my pc was hijacked , thus racking up calls when I was online. I was told by a BT adviser that when these popups appear , even if you don't click into it to read it and just click on the cross to cancel it , it still locks into your pc. I was mad at having to fork out for calls which I hadn't made but I got off lightly though compared to some people and even though I now have broadband , I still wouldn't click on it. You never know what could be attached to it.