As for who else, besides espionage services, is in on the game or compromising people with sex - that's less obvious and their are far fewer examples.
It takes considerable resources to recruit the 'talent', set up the trap, have the location wired, etc.
I'd never heard the term "brownstone operation" for these sorts of things, but I've know the term "honeypot" or "honey trap", which I'm sure predates the Barney Frank scandal.
Wikipedia article on Recruitment of spies Love, honeypots, and recruitment and also the article on Sexpionage. There is also this fun article about Honeypots in espionage fiction.
As far as the three events mentioned in the article you link, the Barney Frank stuff happened and was widely reported, I still remember it being on the evening news.
The DC Callboy Operation also happened as the article explain it, and was widely covered at the time. (As the front page newspaper picture shows).
The Franklin Scandal is more problematical. Yes, it happened, but there were never any findings any of it was real, quite the opposite in fact:
Wikipedia Article: Franklin child prostitution ring allegationsI can't say if the narrative presented here is true, for certain, or the allegations that this was part of a coverup are true. 4.5 years for lying for a 21 year old does seem like a pretty harsh sentence though.After investigation, a grand jury in Douglas County, where Omaha, Nebraska is situated, determined the abuse allegations were baseless, describing them as a "carefully crafted hoax" and indicting two of the original accusers on perjury charges.[1] The grand jury suspected that the false stories originated from a fired employee of Boys Town, who might have "fueled the fire of rumor and innuendo" because of personal grudges.[1] A federal grand jury also concluded that the abuse allegations were unfounded and indicted 21-year-old Alisha Owen, an alleged victim, on eight counts of perjury. Owen served 4-1/2 years in prison.[6] Separately, the federal grand jury indicted multiple officers of the credit union for embezzlement of funds, including King.[1][2]
So, back to Epstein. It sure seems like he was running a honeypot operation, but then we also know that he was personally a pervert, so if he was an intelligence asset he lacked self-discipline, and was a very poor one.
Imagine a Russia KGB officer assigned to honeypot someone ending up fooling around with the bait repeatedly, and then getting caught.
It's interesting to speculate if he was running this, was it for an intelligence service, and which one? The CIA, British intelligence and Israeli services have all been speculated about, with some connections offered up for each, but nothing solid yet. And his lack of self restraint I would think would make him much less attractive to an intelligence service.
If you haven't seen it the recent movie (based on a book of the same name) Red Sparrow is the story of a Russian spy trained in the art of seduction who is used to move various Russian espionage programs forward. It's a fun movie. The author is an ex-CIA agent, so like a lot of spy fiction it presumably reflects some level of reality.
