We allow Aperture Science to recruit on campus:

(In case you want to see the full gallery, One, Two, Three, Four.)
Saw this in the engineering building in the computer science area (naturally). The number is for Aperture Science. (No, not really– it’s Valve’s number.) Which is awesome– it’s actually in an out-of-the-way little spot, so whoever put it there wanted people to look for it.
Which means a certain angry AI is back…
“We’re a lot alike, you and I. You tested me. I tested you. You killed me. I- oh, no, wait. I guess I haven’t killed you yet. Well. Food for thought during this next test.”