Click an image for a closer look.
 

	Going up the ramp from the respawn here, the cheater is able to see any enemies entering.
	Here at the top of the yard, with fullbright on and entrances easily visible it would make things very easy for a sniper to pick off enemies. As you can imagine it also makes pipebomb traps very viable.
	In this image we can see that from the entry room balcony the ramp leading from the yard balcony is quite clearly visible. Any incoming enemies can be seen early and quickly dispatched with.
	The view from the top of the entrance room balcony/sniper area shows the ramps to the yard quite clearly.
	In this shot we can see that the water is completely transparent, allowing the cheater to see right into the depths even with GL water transparency disabled.
	Here, standing on one of the ramps up to the yard, the cheater is able to see through the walls to the entrance room, and even to the platform outside the door (which is itself transparent). This provides a huge advantage for defenders.
	From the library here, we can see that the bookshelves and walls have been removed so that the office hallway is completely visible. Obviously the people who hack these maps don't enjoy the little skirmishes around the flag area between attackers and defenders, because using something like this would make them very one sided.
	In this screenshot it is obvious that from the office hallway, little is left to the imagination inside the keyroom. Sentry guns or defenders lying in wait hardly have a hope.
	At the entrance to the gas room, we can see that the cells hallway is very clearly visible. A cheating demoman or soldier lying in wait here would have an easy job of dispatching with any attackers who were trying to cap the key here. Conversely, any cheating attackers are able to see defenders or sentry guns hidden here and avoid them.