A man has been arrested and charged for possession of child pornography and was prevented from meeting a 15-year-old who he'd exchanged explicit pictures with. He was exposed because the child's mother used spyware software to monitor his PC activity. 

Authorities in the US first became aware of the man'sillegal activities after an English woman planted spyware on her 15-year-old son's computer to track his internet activity. Spyware is more normally used by financially-motivated criminals in cyberattacks, but in this case may have prevented an underage teenager from having sex with an adult.
According to reports, the man had been exchanging sexually explicit pictures and videos with an underage boy in the UK, and was arrested as he attempted to board a plane to England, where he allegedly planned to meet and have sex with the teenager.
After planting keylogging software on the boy's computer, his mother discovered the nature of the man's relationship with her son, and alerted police in the UK who, in turn, informed Immigration & Customs in the US.
"There are plenty of companies marketing spyware software as a way for parents to keep an eye on children, but for those worried as to what their kids are doing online the best advice may simply be to ensure that the PC is in a place where other members of the family are present," says Graham Cluley, senior technology consultant at Sophos.
"People need to think very carefully about using spyware to monitor other internet users' activity, as they could end up getting in trouble with the law themselves."