The Internet dating stigma no longer exists, and it's about time. But just because looking for love online is more mainstream, that doesn't mean you should let your guard down completely. After all, it may be easier to meet that special someone ‑- but it's also easier to be deceived by someone else's special someone masquerading as a bachelor. How can you avoid falling for a married man's cyber line? And what are the warning signs that the guy on the other end of the cute emails is otherwise engaged? Take note of these tips.

Cybersex, Lies and Video Tape

Jill Jones discovered the hard way that the boyfriend she'd met three months earlier through Match.com was married: His wife called! Jill, a 27-year-old Washington, DC, marketing executive explains, "Since he lived in a different city ‑- Roanoke, Virginia ‑- it was easy for him to sneak around." She says, "Although he made excuse after excuse about why he continually had to cancel a date at the last minute ‑- one time claiming he'd been in a car accident ‑- I got suspicious only after I knew everything." There had been numerous red flags. For instance, he only called from his cell phone while driving in his car. It turns out that Joe (not his real name) was talking to several women online. According to his wife, Jill was the only one he'd actually met and kissed. [Editors' note: Awkward conversation, anyone?] Jill recalls, "He contacted me a few weeks after he was busted and said how much he cared for me and that his marriage was on the rocks. Blah, blah, blah. I hung up."

Diana House hears stories like this dozens of times a day. House founded the background-check service DatingChecks.com to ensure women that their online boyfriends are being truthful. House, who has worked with thousands of grateful clients, says flatly, "Around 40 percent of the guys online are misrepresenting themselves in some way. The Internet is a perfect place to pretend to be someone you're not." Another investigative option is PublicData.com. Says 50-year-old Bobbie Henson, a Dallas media relations expert who met her husband online, "I used the site to view a man's driver's license. I could then click on his address and see the driver's license of anyone else living at that address. So if he was married, it would come up on the search." Or, if you know his name and the town he lives in, simply try WhitePages.com, where there's a chance the Mr. ‑- and his Missus, if he's married ‑- are both in the book. That knowledge is useful, but it can be painful once you've come to care for a lying lad. So why not start your sleuthing before you meet or very early on?

One sigh of relief: Some states are now requiring online dating sites to reveal up-front whether they conduct criminal background checks on their clients (which disclose not only criminal records, but also marital status) like True.com does, for example.

Is Your Profile the Problem?

If you continually attract married men on Internet dating sites, it might be something you're doing. Author Lisa Daily suggests, "Make sure the language in your profile does not convey that you're needy, desperate to find someone or looking for a white knight to come rescue you." But don't blame yourself. It's not your fault that you're being targeted. Mary Waller, PhD, points out, "It doesn't make a difference if your profile says 'no married men' or comes across like the head of the Ladies' Puritan Society. There are always lurkers and lookers."

Wynn Hartler, a 36-year-old Chicago educator, says, "I was on Match.com for a total of 36 hours and met a very aggressive married man who did not tell me the truth until we had corresponded extensively through several emails and a phone call. He even posted someone else's picture!" On a very positive note, during her brief foray into online dating Wynn did meet someone. A single someone. "We took it offline pretty quickly, and things are going great."

Clear-Cut Clues before You Meet

His profile is photo free. Yes, this might simply mean that he's camera shy. But then again, he may be hiding something. What married man wants his picture accessible to tons of people, some of whom might know his wife?

He lists his marital status as "separated." Judith Lever, a 40-year-old magazine editor from New York City, briefly dated a guy she met through JDate.com. She sighs, "He said the marriage was over. It turned out, not only was he still living in the same house as his wife, they were sleeping in the same bed!"

His home phone number is privileged information. Once you've spoken, he should be comfortable handing out those seven digits. If he's not, proceed at your own risk. Debra Daniels, a 37-year-old executive from Boston, explains, "He might say, 'I always use my cell,' or 'I just moved and haven't hooked it up yet,' or 'Call me at the office because I work all the time,' but more likely, he's just working you." Debra says, "If I suspect he's married, I call him out on it right away, and, magically, he never calls back."

He's in no rush to meet ‑- or he can't wait to meet. Lisa Daily, author of Stop Getting Dumped!, says, "Some married guys want to continue their online flirtation forever because that way they feel that technically they're not cheating. Other married guys want to make an immediate date because they're only interested in a fling."

Warning Signs Once You've Met

Sex is his primary interest. Infidelity expert Ruth Houston says, "If he brings it up early in the first phone conversation or on the first date, there could be a reason for that." Debi Rosen, a 32-year-old banker from Milwaukee who made the married-man mistake, says, "Initially I felt flattered that Peter was so hot for me. I slowly realized that sex was all he wanted because everything else he got from his wife."

You're not invited into his home or into his life. Houston, author of Is He Cheating on You? 829 Telltale Signs, warns, "Watch out if you don't get to meet his family and friends and he's very secretive about them. Also, be careful if his place is off-limits or he's only available at odd times." Houston suggests coming right out and asking if he's married. She says that if he's lying, he'll probably do one of the following: beat around the bush, hesitate, break eye contact or touch his nose or earlobe before answering.

Your Best Bets for Internet Dating Success

Word your profile meticulously. Don't be too provocative or suggestive. That can attract the wrong people. Suggests therapist Dr. Nancy B. Irwin, "Make it clear that honesty and integrity are your hallmarks." You still might hear from a few married men, but don't let this shake you. Good guys are out there.

Cut your losses. There is no way to initially tell for sure that someone who seems like the catch of a lifetime is actually withholding important information. Dating expert April Masini advises, "Weed out the undesirable dates as quickly as possible by being a 'conscious' online dater." This means doing some detective work. Masini, the author of Date Out of Your League, suggests, "Ask where he went to school, where he works, what he does weekends and at night, and see if the answers sound like a single guy's answers. Trust your instincts."

Be positive. Dr. Irwin says, "If you focus on 'all I get are the married liars,' guess who will keep coming your way? Focus on attracting men of integrity." She insists, "Let go of your resentment toward the losers. They're just stepping stones to your ideal mate."