The Surveillance Van is one of the six vehicles which can be acquired in the first level of The Simpsons: Hit and Run. It is a black van with a camera and a large satellite dish on top of it. It appears to be based off of a 1981 Chevrolet G20 Panel Van.
In the level 1 mission "Flowers by Irene", Homer sees the van outside the Simpson's house, and follows it to Mr. Burns' mansion. Later, he accuses Mr. Burns of spying on Springfield, but Mr. Burns reveals they were just pizza vans and fires Homer.
In the traffic of Level 2, similar vans appear. These ones have long-distance cameras instead of satellite dish, and have "Black Van Pizza Delivery" written on the side, furthering the joke that the "Surveillance" vans were really just pizza vans.
Although it only appeared in The Simpsons: Hit and Run, a similar vehicle appeared in "Bart the Murderer" where, while Marge is voicing her concerns about Bart being involved in the Mafia to Homer, she asks why it would take over two weeks for a Pizza Delivery Truck parked out on their lawn to deliver a pizza to the door. It is implied that the "Pizza Delivery Truck" was actually a surveillance vehicle issued by the United States Government to spy on the Simpson family, as it cuts to inside the van and apparently heard Marge's question, and drove off as if they realized she was on to them only to be replaced by a "Flowers by Irene" (FBI) delivery truck.
The surveillance and spying can be done through CCTV Cameras but in that case, Bart and his Mafia contacts will get alert, which might cause a chaotic situation that would waste all hard work of security agencies, as they have not grabbed any vivid evidence yet.