I mean, unfortunately I have to be somewhat vague given both contractual and legal confidentiality requirements (identities and identifying details are highly protected by law in sex crimes cases, particularly those including minors) but I can tell you that there are definitely high volumes of both domestic and international trafficking, quite a significant bit of which is in the 12–18 year old range. You dismiss the advertised language discussing youth as not being indicative, but again, I’m telling you from experience and from the testimony of victims in open court, it is intentionally coded language designed to get past, among other things, the Backpage automatic filters. Other such codes include: references to speaking greek/showcasing international talents referring to anal or other “extra charge” activities, any number of codes for being drug friendly, etc. These are real things, this is real language that is used specifically to advertise it, and they are common codes that, most importantly, buyers understand and know to look for. Internationally, women are smuggled in all the time for sex trade, and most are underage when they get here. Domestically, it’s often runaways or girls in bad familial situations who are picked up/enticed online and then sent bus tickets to “come party” or something similar. They think they’re getting into something consensual (setting aside whether a 15–17 year old legally can consent to such work) but they arrive and find themselves in a coercive situation. A common practice is to take her ID and wallet when she arrives, “for security” or “to keep it safe so you don’t get robbed,” or whatever. What it really does is prevents that person from getting on a plane or running.
I can’t make you believe that crimes are real since you’re obviously inclined not to, only assure you that I’ve seen it with my own eyes, heard it from the victims themselves, and in at least one case from the trafficker trying to justify and explain his actions. But to be frank, expressing your doubt and skepticism as to the reality and severity of this problem while saying things like “I have no interest in looking to see for myself” is up there with denying the moon landing, claiming that 9/11 was an inside job, and wondering if a ball will come down to earth again if you throw it up in the air. There’s plenty of evidence out there to show you how big and real a problem this is; you are openly saying you refuse to look, so therefore you choose to believe it’s not real.
Also, you seem to misunderstand what trafficking is in the first place. Trafficking largely isn’t about “kidnapping,” and the Amber alert has almost nothing to do with it. It’s largely about seducing someone into a trap, often via deception, addiction, and/or financial coercion (such as a promise to get someone into America where they can then work and make a living), and keeping them there via force, fraud, or financial abuse. It’s much more akin to indentured servitude, where you entice someone to come join your sex trade with promises of presents, money, drugs, whatever appeals, and then you dole out just enough money, affection, resources, whatever, to keep them alive and working for you — but not enough for them to run.
It’s very real, and it’s being investigated and, fortunately, successfully prosecuted every day in America. But much like combating drugs or any other vices, the buyers greatly outweigh the enforcers in both financial support and in numbers.