Alright… You made me get into it. If you go into your Real Debrid account settings and make sure your download port is set to “secure” then your ISP cannot see what you are downloading. Everything is encrypted, the same as a VPN. The difference is that your ISP can see that there was some traffic between your IP and Real Debrid. Keep in mind it’s not illegal to stream, just to download. This is also where the benefit of a multihoster comes in because they are the ones actually downloading to their servers.
Now, Real Debrid does keep a log of your activity for up to one year and technically could release it to authorities if ordered to. There is NO WAY AROUND THIS!!! When you sign up for Real Debrid you have to have your VPN off because Real Debrid logs your IP address. This is how they control account sharing and people streaming from multiple locations simultaneously. So, even if you are using a VPN when you stream, your ISP can still see when you went to the website and signed up for an account. That’s all they would need to try to get your account history from RD. So if you weren’t paranoid enough before… you’re welcome now!