Dinner, Movie -- and a Background Check -- for Online Daters

"No dating site wants to admit there's bad people on their site," said Dave Evans, a consultant to the online dating industry who blogs about it on OnlineDatingPost.com. Offering screening or other security add-ons might suggest to users, " 'you better pay this or you could get raped or dismembered,' " he said, which "is not an inviting come-on for new members."

Some daters turn to College Park-based Trufina, which verifies someone's age, identity and address -- a service it began offering free last week, figuring that will draw customers willing to pay an additional $9.95 for criminal checks. Several other background-check firms, like Intelius, which built their businesses doing criminal checks for employers, are increasingly finding customers interested in researching their dates.

There are also other companies like Jangl, a start-up that offers free temporary phone numbers for eBay customers and dating singles who, at least initially, might want to keep their real phone numbers to themselves. Another company, Tossable Digits, offers a similar service for a fee.

Since November, Match.com has gotten more than 500,000 members to test its MatchTalk feature, which uses Jangl's technology. The service asks for members to enter their phone numbers into the Web site, which generates a phone number that can be used to make calls between the two dating prospects without disclosing their actual numbers. The service is temporary: A couple can give up the temporary number if they get serious or if they call it quits.

"We're excited by the take-up," said Jane Thompson, senior vice president of Match.com in North America, which plans to soon charge $6.99 a month for the service. It allows users "to screen people and remain anonymous, yet still get another data point on someone's personality," she said.

One site promises one-stop shopping for dating researchers: DontDateHimGirl.com is a repository of 18,000 men whose former girlfriends allege they are cheaters, liars or two-timers. The database, started in 2005, comes complete with comments from the accusers as well as responses from the accused.

"Do not let the smile fool you," says an anonymous post next to a photo of a handsome, shirtless man wearing boxing gear. "This man is the king of cheaters . . . He has never been fait[h]ful to ANY of the women he was in a relationship," his accuser wrote. "STAY AWAY FROM HIM!"

DontDateHimGirl.com has been sued for defamation by a Pennsylvania man. The site's founder, Tasha Cunningham, said her firm is not liable for third-party comments about men. That suit is still pending.

Of course, not all dating filters are high-tech. After a string of bad dates and poor screening on her own, one D.C. woman recruited the best quality control she could find: her mother.

From her home computer in Michigan, the mother poses as her daughter on Match.com, corresponding with prospects and arranging meetings on her behalf. Her mom is familiar enough with her physical, educational and professional preferences in men to pick the most promising candidates.

"She knows me really well," said the woman, who spoke on the condition of anonymity because she did not want to damage her professional career. "She's my mother. She cares about my best interests."