@tdemin What ISP is that?
Are you sure it's not some "Internet shield/antivirus/etc" thing they automatically added to your subscription, and which you can ask them to disable?
@Wolf480pl ER-Telecom (commonly aliased as "Dom.ru"). And yes, I'm pretty sure I've disabled all of the "protection" features that were enabled by default (of course that was the first thing I did after signing up for their service. Was quite surprised after seeing SMTP being blocked by default).
That sucks :/
OTOH, it's a fun reminder that you're supposed to use HTTPS... if only all websites supported it...
I'd seriously have a hard time deciding whether to set up sth like a VPN or proxy through ssh -D, or just live with it and be constantly reminded that I'm not supposed to use HTTP....
Regarding the VPN/proxy solution, it's good to have a VPS/dedi. I can only imagine how much it sucks to not have one and have to look through all those shady 3rd party VPN services.