Users who get e-mails and chat messages from strangers beware! Attachments could be carrying rude or even dangerous surprises. One internet peeper hacked into the laptops of 150 schoolgirls and secretly observed them day and night over their webcams. This is just one case that was discovered and the perpetrator arrested. But criminal investigators are seeing more and more of such activities. One potential back door is the chat program ICQ, which strangers can exploit to send infected files. Once opened, they can set up an online connection to the unsuspecting victim's computer, allowing the hacker to take control of it.