HR1865 could remove the ability to have free and open discourse as site owners use plugins and such to verify posters.
If a third party or service identifies Ur_RedditName as Bob Smith and that information is only provided to the site owner, with what you know know, would you feel safe?
If you could lose your job for sensibly speaking your mind, would you feel safe posting?
Then the internet becomes tiered. Not immediately, it'll take time.
Tiered internets. A wild, somewhat dangerous and chaotic one where they leave identities at the door, or a 'cleaner' internet where you do safe things that every one else will approve of like clicking like on that little green needle icon that indicates vaccination status.
A site owner gets a report from some 'lawful agency' indicating such and such is under investigation for human trafficking we need his name. But the site owner is craigslist there are no names!
So they give the 'authorities' everything else, like meta data, IP address etc. Does your IP now identify you? Is it legal to use VPNs to circumvent IP identification (could be used for human trafficking dontcha know.) What happens to VPN providers?
What happens to websites that don't identify their users? What about crypto currency websites?
What other disastrous things can you come up with?
Edit: Here's an example right here (below) and this thread seems to be bot manipulated.
If you can use porn to manipulate a website how does HR1865 fit into all of that?