LONGVIEW, Wash. - A Colorado man convicted in the past of sexual assault and extortion is under arrest after police say he tried to sexually solicit a 12-year-old Longview girl through the Internet.

Investigators say Benjamin Stribling, 25, asked the girl to send him nude photos of herself while chatting with her on Teenspot.com, a popular social Web site.

Unbeknownst to the girl and Stribling, her parents had installed spy software on the computer that alerted them to the content and destination of the messages.

They alerted authorities who tracked the messages to Stribling.

Police said Stribling apparently had sent about 100 similar messages to young girls around the country.

Computer safety experts advise parents to install one of the many "spy" software programs on computers used by children.

The programs can be tailored to alert parents via e-mail when certain words or phrases are used in e-mails, chat rooms or instant messages.

The price for the software ranges from $40 to about $100.

• Guardian Monitor Family Edition
• My Kid Is Safe
• Spector Pro
• PC Tattletale
• Barracuda Web Filter