Reddit blocks all search engines from crawling their comments, essentially blocking all user generated contents. See this directive in https://www.reddit.com/robots.txt `Disallow: /r/ /comments/ / / /*` But I can still search Reddit on Google. How does Google manage to get the data?
The relevant robots.txt rules are:
User-Agent: *
Disallow: */comment/*
Disallow: /r/*/comments/*/*/*/*
The url for the comment sections looks like: https://www.reddit.com/r/[subreddit]/comments/[id]/[slug]/. This doesn't match the above rules because there's only 2 parts after "comments", not 4 parts as specified by the rules.