Public Pay Phones
We may still see public phones around our cities but nobody uses them very often. Often vagrants vandalize them or homeless people take shelter in them. But they rarely serve their primary purpose anymore for one obvious reason. Everyone has cellphones now so it’s not necessary to use public phones.

Meanwhile, fewer people carry coins so that makes them even less convenient. Another problem was that law enforcement could no longer tap them without a warrant. This made it easier for criminals to engage in deals without worrying about the police. That’s an interesting factor that opens a major can of worms (via The Atlantic).