And seemed out of context. Plus there were no misspelled words.

It wasn't until she asked him about whether he'd sent the messages that Dan realized someone -- unbeknownst to him -- had logged onto his Facebook account. The obvious suspect: his ex-fiancee, who had been cyber-stalking him since he began seeing Alicia. The ex would have access to his password, since he'd used her computer. She denied it, but all the evidence pointed to her as the sender.

There's been a lot of talk in the media lately about loss of privacy. Usually, these stories involve credit-card theft or anti-terrorism measures. But what about privacy issues when it comes to dating?

The Internet has given us a lot of great things -- dwarf-fetish porn, the truth about Scientology, emoticons, The Superficial. But along with that comes a price, and our privacy is now more at a premium than ever. Those pictures your ex took of you that night you wanted to do something special for her? Maybe you shouldn't have fooled around with her best friend, because now all your co-workers know what you look like in nothing but a cowboy hat and ass-less leather chaps.

Social networking sites are another area where privacy is up for grabs. While it's a convenient way of finding out if someone you're interested in is already in a relationship, it's also a cheap and easy way for others to keep tabs on who you're hanging out with -- something that, with the click of a mouse, can lead to misunderstandings and hurt feelings. Make sure you know what's visible, and to whom.

Then there's the blog. Now that everyone and his mother has one, details of our private lives can sometimes be unearthed with a quick Google search, especially if the blogger is indiscreet. Writing about one's life for all to see means, inevitably, involving friends and lovers in a public forum.

Even changing the names of the people involved is no protection against identification, as I found out when I posted an item about a friend. One night, riding in a cab with her and a co-worker, the co-worker asked her about a detail only a reader of my blog would know. My friend felt put on the spot and violated. She didn't talk to me for two weeks, and asked that I remove the offending post.

In a perceptive recent article in the New York Times Magazine, former Gawker editor Emily Gould writes about how, though it undermined the relationship she was in at the time, she wouldn't, or couldn't, stop blogging about her personal life.

"My blog post was ridiculous and petty and small -- and, suddenly, incredibly important," writes Gould. "At some point I'd grown accustomed to the idea that there was a public place where I would always be allowed to write, without supervision, about how I felt. Even having to take into account someone else's feelings about being written about felt like being stifled in some essential way." So, fair warning: if your date mentions that he or she keeps a blog, make clear what is and isn't off-limits.

The Internet offers plenty of other areas in which amateur sleuths can ply their trade -- bookmark history (you might want to get rid of those "Lindsay Lohan nude pics" search), email (delete or hide incriminating missives; make sure your inbox is password protected), and records of old or recent IM exchanges.