To understand why this works, you have to rewind the clock to the early 2000s. When Axis launched their first cameras, the internet was a friendlier, less malicious place. These cameras were designed primarily for internal networks (intranets), not for exposure to the open web.
The term "inurl" is a Google hacking query—or Google Dork—that instructs the search engine to look for specific text within a URL. In this case, "axis-cgi/mjpg" refers to the standard path for the Motion JPEG (MJPEG) stream on many Axis IP cameras. When these devices are connected to the internet without proper password protection or behind outdated firmware, they become indexed by search engines, effectively making their private feeds public. The MJPEG Format inurl axis cgi mjpg motion jpeg free