• if two people have sex, and one gets paid, that's prostitution and illegal

• if two people have sex, and they both get paid, and it's videotaped, and the tape is sold to others, that called adult entertainment and it's not illegal

According to Scott Horton( H/T FoxholeAtheist):

Note that this prosecution was managed with staffers from the Public Integrity Section at the Department of Justice. This section is now at the center of a major scandal concerning politically directed prosecutions. During the Bush Administration, his Justice Department has opened 5.6 cases against Democrats for every one involving a Republican. Beyond this, a number of the cases seem to have been tied closely to election cycles.

So far it sounds like a simple (although expensive)prostitution case

Jane Hamsher asks some interesting questions @firedoglake

That this has happened does not tarnish his actions as a crusader with regards to the misdeeds of Wall Street. It doesn't negate the very real good that Spitzer did for lots of people with regards to his position as Pitbull for the People of NY.

Everything I've read says he was investigated based on his financial transactions -- cash withdrawals -- in response to reports from his bank(s) to the IRS.

As you've pointed out elsewhere, the Mann Act has been used by federal prosecutors against principals in interstate or international prostitution rings.

But why do you think they're even considering charging Spitzer, a customer, under the Mann Act?

Why are you ignoring, at least in this post, the pain-fully obvious possibility that (absent a plea involving his resignation) they are going to charge him, as the ABC News report says, with structuring -- a species of money-laundering -- under 31 U.S.C. § 5324(a)?

As a former prosecutor of organized crime money-launderers, Spitzer was certainly aware of the $10k+ currency transaction reporting requirements.  He also, at least per all of the press reporting, went to great lengths to deal only in cash, not using Amex or wire transfers.  He appears to have deliberately -- albeit unsuccessfully -- manipulated the system to stay of the feds' financial radar screens, which (as you know, Jeralyn, and Spitzer did too) have been given much more attention post-9/11.

If he's been deliberately trying to evade the federal regs, that's "structuring" -- a federal crime wholly independent from the underlying prostitution or Mann Act.  It's a crime that is only incidentally related, in fact, to whatever went on with the callgirls.

Even many people who believe prostitution should be legalized anyway (like me) find the governor's behavior outrageous. It is practically a guarantee that this prostitution ring has ties to organized crime, leaving him open to blackmail - which is a much more serious matter with an executive official like an attorney general or governor than with a legislator who is one vote among many.

Also, as attorney general Spitzer was infamous for using obscure old laws to put away his targets, especially securities people. And, he busted a couple of high-end prostitution rings himself, accompanied by heavy publicity. The hypocrisy is so thick he should just resign right away to avoid doing damage to the party, especially this year.

   I'd agree that a federal prosecution either for prostitution, financial structuring/money laundering, interstate travel,  or racketeering would be serious overkill.

  He should resign forthwith though. The suggestion above that because he is now Governor and no longer AG or a prosecutor somehow lessens either the hypocricy or the risk of being subject to coercion to use his offices for the benefit of those with dirt on him is absurd. There's also the quaint notion that it's wrong to engage in criminal acts even without hypocricy or creating risk of extortion, and that elected official should be held to some minimal standard of personal conduct which excludes deviously plotting to commit criminal acts.

  Attempts to portray HIM as the victim are desperate nonsense as well. The only thing of which he is a victim is his own behavior.  The real victims are his wife and kids.

For the greater good, he needs to resign NOW.

Then we can say, "Our guys resign, yours think it's all good."

  One might speculate that a pattern of relatively small sums of money being transferred in a short period of time from/through  various accounts to a specific account raised suspicion of concealment but there are I suppose many other possibilities.

Since that weasel Mukasey got in on the strength of Schumer (D-NY) endorsing him, it would be interesting to know if the topic was covered in the private conversation he and Schumer had before Schumer gave Mukasey  the big thumbs-up.

However, in the Village, innocent bystanders are in short supply. And surely Spitzer is not the only member of the New York-Washington, DC axis taking advantage of Amtrak's fine Northeast Corridor service for an out-of-town tryst.

And I would bet that many Villagers who are Shocked, shocked! today are at the same time checking their own personal phone, email, and financial records very, very carefully, particularly those involving out of town stays.... especially during the campaign season. Eh?

Personally I don't give a rat's butt if Spitzer was paying for sex or not. I've always thought, so long as the prostitute is of age, not a victim of the slave trade and willing it's no body's business but the stupid man caught with his britches down and the poor family members that have to be humiliated along with the nitwit too stupid to keep his pants zipped. (Yeah, I do mean Bill Clinton too.)

However, if Spitzer tries to tough this out it will be a non-stop Republican talking point. We all know how the media and much of the public likes sex scandals. If Spitzer truly cares about his party and his family he will resign immediately.