It started at 11:00, when they announced that we were 'advised' not to leave the building. Which then sparked a race for the snack machine on the 5th floor - there were 6 people in the queue for it when I arrived, with more people right behind me. I'm sure cannibalism was setting in by the time I headed back downstairs.
So I dutifully waited for midday, ignored the advice and went over to the main office for lunch (there not being a canteen in my normal building). That was all fine - there were a few people about, and about 5 police officers, but not much exciting. Sadly, by the time I got back from my (not very nice) lunch there were around 40 people milling about at my end of the street, about 20 officers, and a whole load of noise from the other end of the street. And they weren't letting people back into the building (either of them).
So I stood to one side and watched from a safe distance while more police turned up. Then some police vans. Then some more police vans, until finally there were about 12 vans and two Volvo shaped vehicles all wedged in to my end of the road. At which point we were motioned back as the police went into position.
There didn't seem to be any actual trouble though - people were generally doing what they were told and the police were actually being friendly (if firm) towards people. However, after about 45 minutes I got bored of not being able to see much (and I'd finished my paper), so I wandered around to the bridge over the area, which gave a much better view. Sadly, there still wasn't an awful lot to be seen, but I did manage to find someone I knew, who told me that one of the side-entrances was still open, and that there was a spare desk in their area.
I made good use of that, answering emails and phoning my team-mates to let them know I was still alive, and writing a couple of design documents (good thing I had the spare time, eh?), before things calmed down enough for them to start letting people back out of both buildings (still couldn't easily get _in_ but out was ok). So I phoned Jen (co-programmer) and she agreed to bring me my phone, PDA and MP3 player and meet me outside the Usher Hall. She was ten minutes later, as they were only letting them out 5 at a time, under police escort (I think), so I spent the time watching the riot police lounge about, and the rather cool police horses. The whole area seemed to be closed to traffic, making Lothian Road as quiet as I've ever seen it during the day time.
There was a fair number of rumours during the day - including a piece in a BBC report about my building having protestors in it. So far as I can tell the outside carpark got some protestors in it, but as that's entirely open to the air, and has no way of stopping foot traffic, that's hardly surprising.
It wasn't really a riot, more of a disturbance, and I'm glad that both the police and the protestors seemed to be keeping things on a semi-reasonable level.
Hope the rest of you had a day that was at least as restful as mine, if not more so...