Monitors hacked at the U.S. Department of Housing and Urban Development to display an AI video of Trump licking Elon Musk’s toes. “LONG LIVE THE REAL KING.”
Eh, "Access" is a pretty loose term with most of these systems.
There are many different systems to handle screens like this, many of them use simple username/password combos. Like admin/admin.
If the network security team hasn't segregated vlans or domain access well, or they considered the monitors to be a low security item, the internal webpage controlling them might be accessible to anyone on the network.
Heck, this same thing happened at my high school over ten years ago. Someone AirDropped Shrek SFM porn onto the announcement monitors in the school lobby
"Hacked" is misused all the time. "My Facebook got hacked" or "My email got hacked" generally means that the person clicked on something they shouldn't have/leaked their credentials