Insecam lists only cameras that are intentionally unsecured or demo units. They clearly mark location and type. Many top Telegram channels simply repost from Insecam.
For those setting up their own home surveillance. ipcam telegram channel top
A: The channel itself is not illegal, but sharing unauthorized private camera feeds is. Viewing such feeds may also be illegal depending on your jurisdiction. Insecam lists only cameras that are intentionally unsecured