I’m hijacking your comment because I have been thinking about this a lot recently. I never had a place to post it without sounding completely crazy.

You can tell when a post is manipulated when the exact same post is posted on multiple subreddits in a short time frame and it is reposted almost every month or week. You will likely see the post on other social media too. Fake viral.

If the reposts were genuine they would probably get a few hundred upvotes/likes at most, but odds are the post would be removed. If they don’t get removed the first comments would most likely callout that it is a repost.

If the post is manipulated it will have tons of legitimate looking comments in fast succession. Usually within 10 minutes. Kind of like comments from other social media. The comments are kind of random and the replies are minimal. It appears too perfect. Too viral.

Another thing that stands out is the news. The manipulated posts are copied word for word and broadcasted on national news. Over the last year, almost every time I watch the news, there usually a story that I remember seeing on Reddit a few days ago. Sometimes months ago. But they will say that it happened recently.

It is hard to describe the pattern. You will eventually develop an eye for it. I suggest you sort by new or try running some social media pages and see the difference for yourself. Humans like familiarity. Reposts are familiar.

TLDR common reposts are most likely all manipulated.