Unless they put him in solitary confinement, this guy won’t last eight seconds in a federal pen. Especially when the inmates find out he’s in for messing with kids.

I’m not going to pretend to know the law in this area so legal eagles are invited to correct me if I’m wrong: Is it in fact the case that “merely” sexting with a minor isn’t a federal (or state) offense? Weiner allegedly shared some lurid fantasies with the 15-year-old girl who spoke to the Daily Mail, but sharing fantasies — even with a kid — might not be actionable if they progress no further than fantasy and if they’re limited to written text. That’s what I assume the feds are after in seizing his phone. They want to know if this was “mere” sexting or if it, shall we say, developed.

Prosecutors in the office of US Attorney Preet Bharara have issued a subpoena for Anthony Weiner’s cell phone and other records, according to law enforcement officials.

The FBI and the New York Police Department have opened preliminary investigations of allegations that the former New York Democratic congressman exchanged sexually explicit text messages with a purportedly underage girl.

Spokespersons for the US Attorney’s Office in Manhattan and the FBI declined to comment.

John noted last night that the NYPD’s Special Victims Unit is already looking at Weiner. Now the feds are involved. What charges are they looking at?

An obvious possibility is 18 U.S. Code 2422, “Coercion and enticement,” a.k.a. soliciting a minor:

(b) Whoever, using the mail or any facility or means of interstate or foreign commerce, or within the special maritime and territorial jurisdiction of the United States knowingly persuades, induces, entices, or coerces any individual who has not attained the age of 18 years, to engage in prostitution or any sexual activity for which any person can be charged with a criminal offense, or attempts to do so, shall be fined under this title and imprisoned not less than 10 years or for life.

If Weiner told the girl at any point that they should get together and bring their fantasies to life, he has a problem. (And if you’ve ever watched “To Catch a Predator,” you know it doesn’t matter for these purposes whether the underaged girl really is an underaged girl or not.) If memory serves, though, he’s never been accused of that in any of his various other sext-capades. He seems content, as far as we know, to keep his activities confined to virtual space. Maybe he never propositioned the teenager.

But even if he didn’t, he has another problem. 18 U.S. Code 2251, “Sexual exploitation of children,” a.k.a. child pornography:

(a) Any person who employs, uses, persuades, induces, entices, or coerces any minor to engage in, or who has a minor assist any other person to engage in, or who transports any minor in or affecting interstate or foreign commerce, or in any Territory or Possession of the United States, with the intent that such minor engage in, any sexually explicit conduct for the purpose of producing any visual depiction of such conduct or for the purpose of transmitting a live visual depiction of such conduct, shall be punished as provided under subsection (e), if such person knows or has reason to know that such visual depiction will be transported or transmitted using any means or facility of interstate or foreign commerce or in or affecting interstate or foreign commerce or mailed, if that visual depiction was produced or transmitted using materials that have been mailed, shipped, or transported in or affecting interstate or foreign commerce by any means, including by computer, or if such visual depiction has actually been transported or transmitted using any means or facility of interstate or foreign commerce or in or affecting interstate or foreign commerce or mailed.

That’s a 15-year minimum sentence. And that’s just the “enticement” side; receiving child pornography is a separate offense under 18 U.S. Code 1466A. Is there any reason to believe Weiner might have child porn from his 15-year-old sext partner on his phone? There is if you believe the Daily Mail expose: The girl claims that she and Weiner used Skype, that he asked her to undress and asked about masturbation, and that he shared pornographic videos with her. He also supposedly asked her to “dress up in plaid skirts and pretend he was her school teacher.” It’s not crystal clear from the story whether he did this using Skype’s instant message feature or the video chat feature, but the dress-up part suggests the latter. That’s where Weiner’s in obvious legal trouble. If the feds can recover any videos from his phone showing the 15-year-old nude or doing something sexually graphic, he has a problem. And needless to say, if she sent him any photos along those lines and he kept them, uh oh. Frankly, he seems like a guy whose judgment is poor enough that he would keep them.

Here’s the latest development, by the way:

Weiner gave The Associated Press an email, purportedly written by the girl to her teacher, in which she recanted her story.

“Our online chats were never inappropriate,” the email said. “I wanted to publish my story. He was the best candidate to pin the story to. The story needed a hoax to ride on.”

The teen told the Daily Mail, though, that Weiner had pressure her into writing the letter in order to get him off the hook. The feds will know soon enough whether there were “inappropriate” chats.

Exit question: “Top Hillary aide’s estranged husband indicted on child pornography charges” would be quite the October surprise, wouldn’t it?

Update: Lo and behold.