FWIW I too am unable to access reddit using my home (residential) IP. I've never had an account there, so I have no idea why they would block my IP. I also haven't scraped anything, ever.

Previously I could access old.reddit.com, but now that's blocked too. I also can't create an account -- I get "403 forbidden", even if I specify an email address and clear my cookies.

I even created a support ticket about this a few weeks ago, which went unanswered (apart from an automated message which wasn't helpful or applicable at all).

I suspect it might be because I often use RedReader on my Android phone, which is still working somehow regardless of the IP ban.

Funnily enough I can access Reddit through a VPN.