Many years ago I would go to Qantas HQ (Mascot NSW) to eat in their ground floor cafe, as I was working at an industrial site nearby and there was nowhere else to get lunch except for one tradie's cafe, and sometimes you wanted something a bit better. (Mascot is now a totally different place!) While I can't recall what arrangements they had for the public who might appear - I seem to remember nothing other than a security guard to turf you out - I do remember that the cafe, which was open to the public, was full of Qantas employees discussing things that probably should have been kept confidential. If you were a competitor and interested in what new routes they were starting, etc, it would be a good place to become a regular!