I don't want to cause a knock-down drag-out argument so hopefully this will be taken in the non-confrontational, purely educational spirit it is intended...And, if the water you're fishing is your own private pond, completely disregard this.
There have been multiple articles published just in the past few months, among them a recent one by In-Fisherman magazine, on the harmful, often permanent, negative effect overharvest of keeper-size bluegill can have on the size structure of a bluegill population. It was indeed believed at one time by scientists that bluegill could not be overfished, and that removing large numbers of them, even from larger lakes, could do nothing but help. Now there is ample evidence, from several studies done in several states including Illinois, Minnesota, Wisconsin, South Dakota, etc., that proves beyond a shadow of a doubt that overharvest by anglers is permanently reducing the average size structure of bluegill in public lakes all across the U.S. Several states have already enacted regulations informed by this research, including Illinois, Missouri, Pennsylvania, Minnesota, and Wisconsin; those regulations usually include a minimum length, and a drastically-reduced creel limit. Here is a recent article that covers the science behind why overharvest kills bluegill size - there are many more:
Why Everything You Know About Bluegill Management is Wrong – Cool Green Science
Here is basically the same science explained in a more prestigious publication i.e. In-Fisherman:
Managing Bluegills - In-Fisherman
Please, please know that I have already argued with multiple posters on multiple other forums, including this one a couple years ago, about this, and never in any of those instances have I failed to have been personally insulted while at the same time having my seventeen years of knowledge as a professional fisheries manager being entirely discounted along with the reams of scientific research that has been done by fisheries scientists on this subject; please know that I mean it when I say I really don't want to argue, trade personal attacks, etc.
All I want to say is this: there was a time in this country when it was socially acceptable to keep a stringerful of big largemouth or smallmouth or walleye. At some point enough anglers realized that that was a pretty selfish thing to do, and that fisheries around the country were being negatively impacted by this outlook, and enough anglers stopped doing it that it became socially unacceptable to keep ten largemouth from three to five pounds (or four to six or five to ten) each. I still like to believe that bluegill anglers can have the same consideration for their fellow angler that led to the sea-change in thinking thirty- or forty-odd years ago among bass fishermen, and that there have to be bluegill anglers out there that will actually care when they read what their keeping of a coolerful of bluegill every time out is doing to the resource, and other anglers' ability to enjoy said resource.
I speak from firsthand experience. I would personally have multiple world-class public bluegill lakes to fish within thirty miles of me if it were not for overhavest; and not just me, but every angler who lives within driving distance of those small impoundments would have access to that level of fishing. And there are tens of thousands of ponds and lakes and rivers all across the country that would have bluegill fisheries the like of which most anglers have never dreamed of, if enough anglers began thinking of the future of the resource, and their fellow angler, each time they fished.
For those who would counter that it's legal, not too long ago it was legal in this country to smoke in public, long after there was incontrovertible proof that second-hand smoke was the second leading cause of cancer behind first-hand smoke. If enough anglers in states such as Tennessee, Alabama, etc. demanded that their DNRs actually protect and preserve bluegill fisheries just as they do every other popular freshwater species, regulations would follow.