The last time I flew out of SDQ a few weeks ago, there were military guys standing by the exit from immigration, and they were giving anyone who had stayed longer than the 30 days a hard time - I have residency so I was fine, but I kind of hovered to find out what was happening. And it seemed that they were targeting people who had overstayed, even after they had paid the fine, they wanted to know why the person had overstayed, had they changed their flight, what had been the purpose of their visit. One guy was getting very angry with them and it didn't seem to be working.
I think the message is that this has been a long time coming. Immigration rules have been more and more enforced over the years, and sooner or later they are going to insist that anyone on a tourist visa only stays for 30 days. I don't understand why Americans think that this is such a big issue, given that if anyone stays by a minute longer than their visa allows in the US, they are in reasonably serious trouble and usually banned for 10 years from re-entering.