Reddit Migration

Not the guy you were asking, but the ones I found were blatantly obvious because they would copy and reword info specific to the user they stole it from. Like "as a conservative, I wholly support what Ron DeSantis is doing in Florida" changed to "as an unwed teen-aged mother ..." kind of thing. Eventually though the bots are gonna get too good to spot I bet

It's a bit like finding a single thread and unravelling it.
I used to get dozens of these things banned a day, there were a lot of us bot hunters reporting bots.

They sometimes sound "off", stop in mid sentence, reply to people as if they think it's the OP, reply as if they are OP, or post 💯 by itself. Or they have a username that fits a recent bot pattern (e.g. appending "rp" to existing usernames)
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If you see one slip up once, then looking at its other comments will often lead you to new bots simply because they are all attracted to the same positions (prominent but a few comments deep).

Certain subs like AITA and r/memes are more prone to them so I would go there for easy leads.

Also if you check its actual submissions, a karma laden bot will often repost hobby content, then have a second bot come and claim to have bought a t shirt or mug with that content and post a malicious link. Then a third bot will pose as another redditor saying thanks I just ordered one to the second bot. Following those bots leads you to even more bots, etc.

@XiELEd copying you in here.

To add to what other people said: As a casual user who didn't go deliberately looking for bots, I mostly caught them when they posted a comment that was a complete non sequitur to the comment they replied to, like they were posted in the wrong thread. Which, well, is because they were--they were copied from elsewhere in the comment section and randomly posted as a reply to a more prominent thread. Ctrl+F came in very handy there. (They do sometimes reword things, but generally only a couple of words, so searching for bits and pieces of their comment still usually turns up results.)

Also, the bot comments I caught were usually just a line or two, not entire paragraphs, even if they were copied from a longer comment.

The past year or so, they've been in every single thread with more than 50 comments. If you expand the comments and do a little ctrl+f searching, you'll see how they copy comments from users and then repost and have their fellow bots upvote them for visibility. Look at the timestamps on the posts.

I think some people just assume people they disagree with are bots.

Expand the comments and do a little ctrl+f searching. The bots tend to copy a comment, post it as their own (verbatim or slightly reworded), then have their fellow bots downvote the original and upvote the bot comment. You can also see in a new but reposted thread, the top few comments are exactly the same as a previous repost.

That is a good point.

I guess the times I had in mind were where the human had obviously become upset - often when a bot repurposed a reply in a way that made it seem like it was contributing a horrible point of view, so not a real debate.