The Tragedy of the Commons is a well-known example in economics of how a common or public resource can be destroyed through over-use.
Adam Smith's famous Invisible Hand worked differently as he applied it to privately owned resources. Take the richest person you can find, and their wealth and resources are distributed to the poor due to the fact that the rich person will hire others to help take care of the estate. They can't possibly consume everything they own or create, and they can't take care of it either. Hiring someone poorer than them helps to maintain or grow the estate, while benefiting others at the same time. This is in some way the basis for Trickle-down Economics.
A commons, however, is a public space, with no majordomo to place limitations on its use. The tragedy comes in when this public resource is overused to the point that it becomes useless. Normally individuals acting in their own self-interest will provide a net benefit to society through their actions. The problem is that public lands can be overgrazed, roads can be shut down by gridlock, and a once-beautiful park can be spoiled by trash.
The stock market has the potential to be destroyed by those large players who manipulate it in a variety of ways.
I think our phone system has all but passed this point. Between mobile phones, the Internet, and scam calls, something major needs to happen to fix the problems that our common carrier phone system is faced with. There used to be natural limitations on abuses of the phone system, long distance calling rates being one of the biggest. There is no security system in place with our phones, as they were built as a commons, to allow anyone to call anyone if you had their number (and these were published). With the advent of free calling via VoIP, the minimal cost gatekeeper is gone, and untraceable nuisance phone calls flourish. Scammers are riding a dying wave, as fewer and fewer people have a landline anymore, and fewer people answer phone calls that they aren't expecting. There are still a few people left to scam, so they continue trying, and as they do, they hammer their own coffin even tighter.
With many messaging and voice apps available, we still have options to communicate within private systems. This requires that everyone maintains multiple accounts, in order to have the ability to talk with different groups. Those under Apple's spell are locked into their communication tools, yet there are many other providers. Facebook had gotten too big and has taken a stumble because it got away from its original mission and sold out to scammers and advertisers, so alternatives arise. It is a pain to deal with so many protocols and username/password combos, but the pain and cost is what puts up just enough of a wall to keep tragedy at bay.
