It means they have way too much time on their hands.

It means that they are the biggest fucking loser on Lemmy. It’s ad hominem manifest. I once had someone go back months and find a comment I wrote about LEGO say, “Go back and play with your LEGOs.” I replied with, “You pathetic fucking loser! It’s LEGO blocks, not LEGOs.”

All joking aside when that happens I tell the user who did it that they are the lowest and most pathetic of all losers to go back and ad hominem based on someone’s comment history and no longer worthy of interaction with me then I tag them and ignore them studiously from that point on.