I'll answer this for the benefit of other people.
A good place to start would be the actual charging documents or plea agreements, or news articles that summarize them. Here's an example:
https://reason.com/blog/2016/10/10/johns-suppression-initiative-casualties
"Most efforts wind up as they did in Lincoln, Nebraksa—where initial headlines about the August bust announced "12 arrested in Nebraska for sex trafficking related crimes" and "Lincoln teacher among those arrested in sex-trafficking operation." But the ultimate arrest/rescue breakdown for Lincoln?
no underage or adult sex-trafficking victims discovered
no force, fraud, or coercion discovered
four women, ages 23 to 36, charged with misdemeanor prostitution
five men charged with misdemeanor solicitation of prostitution
one man charged with felony solicitation of prostitution
one man charged with marijuana possession
charges dropped against Corey Walcott, who was arrested for solicitation of prostitution
charges dropped for Maurice Briggs, who was arrested for pandering"
You can get a sense of the sleaziness of the people doing these stings here:
https://reason.com/archives/2017/05/25/cops-fight-for-the-right-to-sexually-exp
"In the same interview, however, Case claimed that police "are not out there to go out and find that street prostitute….What we're interested in now is the trafficking." In other words, Anchorage police are arguing that they must be allowed to molest trafficking victims in order to do their jobs."
The plea agreement in the Backpage case is pretty eyebrow-raising, since the prosecutor is recommending no jail time and the fine is only $20,000 - in other words, the 'perpetrator' is being allowed to keep almost all of his profits and walk free - something that a prosecutor would never agree to if the case were strong. (US law certainly allows for much harsher punishments, and the feds had plenty of time and access to build a case.)
This is more likely a face-saving way for both sides ot wind down Backpage, which was already dead as a business. (International operations were shifted to cracker.com a long time ago,.)