People already immersed in the investigation’s details may find that this treatment covers a lot of familiar material and is a bit sketchy in places. But the program does have some rewards even for serious students of the case, including an interview with Michael Pak, Ms. Gilbert’s “driver.” (The absurd euphemisms of the sex trade flow thickly here; sure, these “escorts” have “drivers,” like celebrities do.) What stands out most starkly, though, is just how much of a fact of life the awful business of sex for sale has become in the Internet age. It has obvious enablers like Mr. Pak, but also enablers by inaction: family members and friends who, at least from the interviews here, seem not to have done enough to intervene. Yes, these victims were legal adults, but sometimes 24-year-olds make poor decisions too. With the easy access and anonymity of the Web, that puts them in greater jeopardy than ever.