This is the reason my printers are in a VLAN that can only be accessed by IT work stations and the print server.... As far as my printers know, there are 4 computers in the entire universe. Printers can't be trusted.
I've got all my IP based security cameras & door control devices on one VLAN, switches & wifi access points on one, staff access on one and student access on another, but honestly I'd never thought of sticking printers on their own.
A few years ago some kids pulled a really lame senior prank, and in the process one of the "smart kids" thought he'd "hack" the security cameras...somehow....to disrupt the network so the network between the cameras and the NVR would be disrupted. Because I'm not dumb and compartmentalized and firewalled, all he managed to do is "borrow" a school laptop, which connected him to just the student access network...and accomplish nothing.
I don't think we ever told him. The prank itself was harmless and approved by an admin. But we did have some pretty awesome footage of them trying to be stealthy and talking about how the cameras were down.