I want to jump ahead of the slippery slope arguments that have already popped up in other discussions about this bill:

The bill adjusts Section 230 of the Communications Decency Act. As it stands, this is the part that states owners are not responsible for anything shared on their site by someone else. Backpage has used this to say they are not responsible for ads on their site that pertained to child sex trafficking.

The adjustment would clarify that 230 does not preclude prosecution of state or federal laws that deal with sex trafficking of children, does not preclude civil suits related to such, and would ensure federal liability for publishing material that facilitates child sex trafficking.

As it stands, Backpage has gotten out of prosecution for hosting ads selling sex with children, by stating they aren't responsible for someone else posting the ads, and that they remove ads when seen.

The Washington Post revealed that Backpage had hired outside contractors to bring in advertising from other sites, and a senate investigation found that Backpage had itself edited ads received to remove offensive language.

Finally:

The National Center for Missing and Exploited Children has reported an 846 percent increase in reports of suspected child trafficking between 2010 and 2015, which it found “directly correlated to the increased use of the Internet to sell children for sex.” The center said that 73 percent of the 10,000 child sex trafficking reports it receives each year involve ads on Backpage.

That is a problem. That's over 7,000 reports regarding child sex trafficking, each year, relating to ads found on Backpage.

Will this legislation stop the advertising of child sex trafficking? I don't think so. I also don't think it will affect a website that hosts ads other people place. But I do think it will affect websites that know these ads are happening and have either hired contractors who helped bring those ads in, or have seen those ads and edited them to make them appear less blatant.

Obviously, this won't stop ads placed by people who know there are customers who want children, and thus sell legal age-adult sex under the misleading pretense that the adult is actually a child or underage. And if Backpage's hand in editing ads was only to tell people like that, "Stop selling ads that imply child sex, these are adults, we only deal in adults, and you're selling sex with adults so stop the bullshit," then I don't think they should be considered to have facilitated anything. But if they edited ads that actually were selling sex with children, to make those ads appear above ground, without investigating the seller, without reporting the seller, or without banning the seller from their service, then I do think they share some responsibility.

And, I don't see a slippery slope argument having any ground here. This is very very very narrow, and any slippery slope argument is going to need more than "BUT THE PRECEDENT" to convince me this bill should be worrying.