Without the VPN, your ISP knows you are making a DNS request, but they can’t see what domain you are resolving. A moment later, they see the IP that request resolved to, when you request that site. They can see how much encrypted traffic is going back and forth. When they see that the IP address hosts a porn site, and traffic analysis shows you’re starting and stopping video streams, they know you’re jerking off, but can’t figure out your specific fetish.
With a VPN, your ISP only ever sees the VPN’s IP address. They know when you are sending and receiving traffic to/from that IP, but they don’t know the original source. With traffic analysis, they can probably figure out that you’re watching videos, but they probably can’t distinguish between YouTube and YouPorn.
What the hell are you even talking about?
A post in a publicly accessible forum is a billboard on the highway. You put it up and anyone can read it. You have zero expectation of privacy after having done that.
Changing the speed limit on the highway (“Rate Limiting”) in no way affects the fact that you put up the billboard on the first place. People may be driving by a little slower, but they’re only reading what you chose to present for them to read.
Scraping does not infringe on privacy. The privacy infringement is that you made the post in the first place. Under normal circumstances, you are the only person at all capable of infringing on your privacy. Exceptions would be someone spoofing your credentials to create the post without your authorization, but someone who does that victimizes both you and the forum hosting your post.
What you’re talking about is more closely related to intellectual property protections like copyright. A musician can play their song over the radio without surrendering copyright protection. Nobody else can make (commercial) use of that song just because it has appeared in a public space.
I think you have a pretty weird understanding of “privacy” if you think that you have it when posting a comment in a publicly-accessible forum.
If you post it in a place I can find it, I can scrape it, store it, use it for my own putposes, in perpetuity. You might be able to convince a government to tell me to stop, but there is no guarantee I haven’t stored it somewhere you and they don’t know about.
That’s simply the nature of information. You don’t get to control my memory. Once you’ve put an idea in my head, you don’t get to take it back. That idea you put in my head is now my idea. It’s my thought.
You can’t unring the bell. You can keep a thought private, or you can post it. But once you’ve posted it, you can’t make it truly private again.
Not-a-paywall paywall.