Welcome, OP!
There was a time that CCCs were slashing limits and ratejacking, mostly before the CC Act. Most of the adverse action was due to maintaining elevated balances, having a baddie appear, your credit score lowering, adding new accounts or adding inquiries, etc. It subsided for the most part, though I'm sure it still happens. There are documented cases in here of none of the above applying where posters in here, with 800+ FICO scores, were hit with $10k-$20k CLDs for doing nothing at all. For many it was completely random and there was no reason at all for that action.
I went through it one time with Macys (back in the day when Macys and Macys CLs mattered) and had a CC go from $3200 to $300 and I had a zero balance on it. In fact my utilization was lower than ever before and my reports were better looking than ever before. I called and the CSR said it was due to adverse action. I asked her "what adverse action" and she couldn't answer. I escalated up the food chain and the next said that, so I took it even further. Finally I talked to someone who offered to look at my report and came back on the phone with a mostly-restored CL and got her to admit that the action was totally random and they did batches of thousands of customers, regardless of their credit. IMO, as a biz owner, I see their viewpoint. They are trying to mitigate losses in a down economy. I can choose not to do business with them and if they treat customers poorly, then I don't need their card.
