Webcams are video capturing devices connected to computers or computer networks, often using USB or, if they connect to networks, ethernet or Wi-Fi. They are well known for their low manufacturing costs and flexible applications.
Here webcams were found automatically through a variety of clever search techniques and update several times a day. Their owners may or may not have intended for them to be public, but they obviously are. Some of them are security cams in companies or semi-public places.