After much hesitation, I finally set up a Facebook account. So I wouldn't be seen as a dinosaur, I've also registered on Twitter.com. I haven't been tweeting much, but I'm now part of the throng of folks socialising with their keyboards.

Like many other columnists, I share personal stories to make a point. However, on the social networks I've limited my communication to my professional persona. For example, I don't list my date of birth. Heck, my kids are not even sure how old I am. I've been 29 for many years. If I want my friends to know where I'm vacationing, I'll call them. Ditto on my dinner plans.

My fans or critics will just have to contend with professional conversation because, in a nutshell, I'm paranoid. And you should be too if you're gabbing about your life on various online social networks. Like a pickpocket working a crowded public venue, cyber thieves may be collecting information that makes victimising you so much easier with all the personal data you provide.

Consumer complaints of online crime hit a record high in 2008, according to the Internet Crime Complaint Centre. The centre is a partnership between the FBI, the National White Collar Crime Centre and the Bureau of Justice Assistance.

The centre received more than 275,000 complaints last year, up 33 percent from 2007. The total reported dollar loss from such scams was $265 million, or about $25 million more than the year before. Of those complaints with a reported monetary loss, the average individual was scammed for $931, the center noted in its annual report on Internet-based crimes.

Although identity theft falls into an area of Internet crimes that together represented less than 10 percent of all online-related complaints, federal and private experts caution people about increasing their exposure to Internet criminals.

The more a criminal knows about you — your likes and dislikes, your friends, where you grew up, your drama — the easier it is to con you. The vast majority of perpetrators contacted complainants in the federal report either through e-mail or via websites.

"Sophisticated computer fraud schemes continue to flourish as financial data migrates to the Internet," said Shawn Henry, assistant director for the FBI's cyber division. "It also underscores the need for continued vigilance on the part of law enforcement, businesses, and the home computer user to be aware of these schemes and employ sound security procedures."

The Chubb Group of Insurance Companies recently issued a warning about divulging too much information on social networks.

Tweeting about your Memorial Day getaway plans?

One of your Twitter followers, some of whom might be strangers, may see it as an opportunity to burglarise your home. If you want to tweet about your vacation or holiday plans, do it after the fact.

"Not too many people are giving second thoughts to the personal information they provide, especially the more youthful users," said Peter Spicer, communications manager for Chubb Personal Insurance. "People don't realise that as they drop information someone may be building a composite of who they are."

Spicer said the insurance company hasn't seen a demonstrable increase in claims directly connected to social networking. But the company is exploring what financial dangers people are putting themselves in by telling all their business on these sites.

Chubb offers these tips to help protect you from identity theft or a financial loss:

— Birthday blackout. Never divulge your date of birth online (month, day or year). It can be used for identity theft or to answer a security question.

— Pet privacy. The name of your pet is a common security question, so keep your pooch's name private or avoid using it as your security answer or password.

— Trash talking. Increasingly employers are searching online for information about prospective hires. So don't trash your last employer or you might risk losing a job opportunity.

— Neighbour nastiness. You may have an incredibly bad neighbour, but be careful about posting comments about your battles. Derogatory comments can be used against you in a defamation lawsuit, Spicer said. The same goes for your children. Talk to your kid about going public with their conflicts. "The power users of these technologies are kids," Spicer said. "If they are talking about other kids, they may find themselves with their parents in a courtroom." Even if the lawsuit has no merit, there's still the cost of a defense. Personal liability coverage under your homeowner's policy can provide some protection, but the policies are limited, Spicer said.

All of these tips may seem like simple, common sense. And yet when I view the postings of friends and strangers, I see some of the listed mistakes. If you want to tweet or post things about your life, just remember that TMI (too much information) could cost you.

Readers can write to Michelle Singletary c/o The Washington Post, 1150 15th St., N.W., Washington, D.C. 20071. Her e-mail address is singletarym(at)washpost.com. Comments and questions are welcome, but due to the volume of mail, personal responses may not be possible. Please also note comments or questions may be used in a future column, with the writer's name, unless a specific request to do otherwise is indicated.