Wi-Fi squatter
n. A person who lingers in a public location to use its Wi-Fi internet connection, or who uses such a connection without authorization.
Other Forms
Café owners have tried a variety of tactics to foil Wi-Fi squatters. They put out signs that ask laptop users to share tables or point them to nearby Wi-Fi hot spots such as public libraries.
—Jessica Guynn, “Coffee shops are taking Wi-Fi off the menu,” Los Angeles Times, August 08, 2010
Two men have been arrested on suspicion of "wi-fi squatting" after allegedly logging on to another person’s internet connection illegally.
—Ben Guy, “Arrested over ‘web squatting’,” The Journal, February 23, 2008
2002 (earliest)
Unauthorized access to the Internet: Even if you firewall your intranet away from your WLAN, what stands between Wi-Fi squatters and your Internet uplink? If your answer is "nothing," unauthorized stations can compete with legitimate users for WAN bandwidth, and your enterprise could be liable for misdeeds launched from your WLAN.
—Lisa Phifer, “Understanding wireless LAN vulnerabilities,” Business Communications Review, September 01, 2002