I am not naïve about the sexual encounters among strangers that are frequently facilitated by free ads posted on Craigslist.

I mostly think of it as unremarkable, consenting adults doing what they like.

Prostitution doesn't generally trouble me either, except of course where women, or men for that matter, are victims, manipulated and made to participate without consent.

Naturally, that deserves the full attention of law enforcement.

The campaign in 2010 by then Attorney General Richard Blumenthal, in which he tried to crack down on prostitution ads in Craigslist, struck me as a bit priggish.

He called the adult section of Craigslist a "blatant internet brothel." Indeed.

Still, despite my laissez-faire attitude toward the topic, I found a recent Craigslist ad, brought to my attention by a reader, troubling.

I should say by way of warning that I will be suspending some rules of good journalism here. This all comes to me by way of an anonymous reader, and so everyone is welcome to join me in deciding whether it is fact or fiction. I am leaning heavily toward fact.

The ad, which is certainly fact, is worrisome on its own, whether you also consider what the anonymous reader adds about communicating with the person who placed it.

In the end, it's all an extension of the murky, anonymous and wispy digital market that is Craigslist.

"$100/hour _ Attractive females for medical role play (Near Storrs, Ct)" was the headline for an ad posted Sept. 14.

Clicking on it would bring you to the body of the ad, featuring a picture of a gynecological examining table in a doctor's office, stirrups open.

The copy under the photo explains the person placing the ad is looking for female models, ages 18 to 35, preferably UConn students, to play a patient in a "realistic medical exam scenario," paying $100 an hour with a $250 minimum.

"You don't have to be a runway model, as long as you're in good shape overall and have a cute face," the ad says.

The reader who brought the ad to the attention of The Day and UConn police identified himself to me as a man in his late 40s who lives in Stonington.

He said he came across the ad while trying to place one himself in the art/medical/design section and said he was disgusted by what he saw. He decided to engage the would-be gynecologist and began an email conversation, posing as a 22-year-old UConn student named Anna Salinger.

The result was a cat-and-mouse correspondence in which the man placing the ad — he calls himself Chris — tries to lure Anna into meeting him for an exam lasting two hours.

He tells Anna that he wants to do this role-playing because he has a phobia about his wife being stressed by visits to the doctor and the best way to address his fears is to conquer them, like overcoming a fear of deep water by learning to dive.

He is soothing in the emails, assuring her that he will be respectful and ensure her safety and privacy. He describes himself as attractive, educated, with the means to buy the props for medical role play.

"I would continue to assess your responses and reactions to ensure you're comfortable," he said in one email.

He also tells Anna he is looking for someone who will enjoy it, too. He said he is worried about later being burglarized or blackmailed.

"I'm not interested in someone who's in it just for the money, as it's supposed to be something fun and exciting," Chris writes.

Anna is both stern and seductive in suggesting she might play along, all the while trying to get Chris to cough up a phone number or address.

He, in turn, resists, and you get the sense in reading the dialogue that he is finally catching on that he is never going to get Anna on his table.

It's true I think consenting adults should be able to do whatever they want behind closed doors, even playing doctor and patient. But this strikes me as something much darker, from deception or entrapment to maybe something much worse.

I was a little sorry to learn Anna was a ploy, because, in first reading the emails, I came to admire the pluck and guile of a 22-year-old college student trying to trap a creep.

The reader also sent along an email he got from a UConn police officer who responded to a "crime alert" email he sent. The officer wanted contact information for Chris.

It was good to know UConn police took the complaint seriously, although I'm not sure exactly what crime they could investigate.

Maybe this was the kind of ad Attorney General Blumenthal had in mind in his attempt to crack down on the smutty side of Craigslist.

This is the opinion of David Collins.

d.collins@theday.com