This is a non-legal corner summary exercise of the worst nightmare of how Reviews can be used against hobbyists and providers, from the perspective of someone who taught federal evidence in another life. A married hobbyist pal from the health care world in the NE asked me to explore the problem carefully with the rules of evidence in hand. This is what I found:

LE sometime really wants to GET some people whom they know are hobbyists or providers. LE has little sympathy with prostitution and Johns, as they characterize this, nor with cutesy disclaimers and the doublespeak talk about "companionship." All they may have to start with are reviews, from different cities & States, with anonymous tags. There is usually vivid detail of bbj's, Greek with porn stars, amounts paid, general location, approximate dates, etc. LE may also want to prosecute a few agencies, and ensnare a hot porn star & porn agency for the media publicity. They can easily find ten reviews from say "Ms Naughty - the French & Greek Mistress," who travels all over for "companionship," and whose webpage is "not a solicitation for prostitution." Those disclaimers really crack up FBI agents we can be sure. (Sound of donuts and coffee spilling! LOL)

The targeted male "Mr OJ" flies to see some women. He flies in others to see him, always crossing state lines in interstate commerce. He encourages even more to tour his home city, Boston for instance. He pays with cash, uses CC's only at hotels, and regularly withdraws from ATMs to keep his cash stash handy.
He uses both indys and agencies.

First, LE prints out all of their reviews and identifies possible crimes and potential witnesses, such as the ladies in question, and the agency operators, the hobbyists who posted reviews of Ms Naughty.

You realize that if Mr OJ had been videotaped by LE making these reviews as an interview, they would be equivalent to confessions to multiple  crimes insofar as LE is concerned. In the words of evidence rules, each review could be a party admission against penal interest, a recently recorded recollection, a statement of mental condition following a session, and a regularly kept business record by the Review Board. Those are multiple grounds for admission into evidence. The problem for LE is authenticating the reviews as statements made by our hypothetical Mr OJ. LE can do this in several ways.

One is to go to the agencies and indys with search warrants, arrest warrants, and threats. Providers are much easier to find than reviewers, and most have info on Mr OJ, such as date of encounter, hotel room number, maybe even credit card info. They sing, or are compelled to by court order, perhaps given immunity. The CC# or tel# leads to Mr OJ's, medical office, home or both, and his wife answers the door. LE seizes his files, records, receipts, diaries, personal & biz computers to verify the e-mail address and everything else they need.

LE method two is to go to the Review site, HnH in Chicago, TBD, ASPD in Texas, TRB in Seattle. LE hits them with search warrants, takes, and studies their servers and computers to verify the ID of Mr OJ and authenticate the reviews by him and those of Ms Naughty. LE comes up with e-mails, posts, and reviews, and at least a CC# or po box address. LE threatens the Board with conspiracy charges. Nobody has an offshore server, so the data is in there. An offshore server could withhold its contents. It happens all the time in various other areas of activity. That would not make things worse.

Then LE draws up charges: Mann Act for facilitating transport  across state lines for unlawful sex; Travel Act racketeering; prostitution; conspiracy; soliciting; and both felony statutory or common law sodomy & adultery. Maybe a little money laundering or tax evasion. LE offers the reviews as evidence of those crimes, as actually admissions and descriptions.

Authenticating the e-mails and reviews is the hard part, but that is what cybercrime LE people do all the time.

The lesson to Mr OJ is not what he wants to hear. It is probably too late. The reviews are there. LE has probably long since made copies of all of them and started investigating. The links of the e mail addy and posting names are weak ones. Too many people know. Too many paper trails exist. The database is too huge for selective deletion, and that raises questions of obstruction.
We all need to know that anonymity is many cases is an illusion, to hope for the best - being ignored - and to become better prepared for the worst.

There has been a pattern with the feds in hot button areas, that you can see by going through US Atty websites. A few prosecutions each year for porno, child porno, ID theft, other select areas. I expect we soon will see a few federal and state prosecutions in each district of a few hobbyists and a few providers. Fed resources are finite. Some will be very unlucky. Many will be frightened out of the hobby.
I do not like my conclusions on this at all.
I'd almost like to see my own reviews deleted and made unrecoverable. I'd like to get all those bbj's back too! NLOL