The latest case to come to our attention involves someone who changed a traffic sign in Northern California to read, "Caution Loose Gorilla!"
Just last week the same sign flashed the message, "Smoke Weed Everyday."
The sign is supposed to tell people that a road in the Placer County city of Loomis will be closed for pipeline construction.
Placer County Water Agency Senior Engineer Tony Firenzi told the Sacramento Bee it took skill to change the message. The unknown hacker needed a keyboard and had to bypass some systems.
Other recent instances of highway sign hacking have included electronic messages in Maine and Massachusetts warning about zombies.
Oct. 12, 2012 - "Zombies Ahead": Construction sign tells Maine drivers to be very afraid
photo: CBS Sacramento/Josh Carroll