Ask HN: Legal texts from websites, how to trust it?

While using the web, we accept many privacy policies and terms of services, but it feels weird.

Unlike a paper contract, where I have a copy of it, on a website, I've never saved a page from one of those websites, and they could modify it without warning me.

Is there a website that monitors this? Or there's some industry standard that every website follows it and I'm being overconcerned?