I've been seeing more of that across the platform. I can't remember where I saw it first, but it's frustrating. I don't have the same number of commenters you have, so I tend to recognize most of the people. It's got to be tough to always be questioning if the person is real or if it's just a bot trying to scam you for a little handout.
It's sort of scary that scammers have reps into the 50s now. I was happy that I had reached 55 because then people would know I was legit. Nope. There are plenty of people with similar reps who have used bots or a voting network to boost their reps. The comments can look legit, but if you look into them more (like in your case) you find it's stolen from somewhere. It's just sad.