I finally have a wristband for 26C3. The wristband is what is controlled on the entrance. I had preordered the ticket and paid by bank transfer, and the receipt with the barcode only arrived on december 25. In earlier years, you came on the 26th, crashed in the hackcenter, and at some point, when there were only ten people in the queue at the cash desk, you got your ticket easily.
Well, this year, things were a little different. First, there was a semi-public ticket presale. What's more, rumors about a very limited number of tickets were floating around. And finally, while the cash desk was said to open at 2000, the software was not ready by then (!) and the opening was deferred to 2130. The "fast line" cash desk for people with presale tickets was only opened around midnight, when I had already given up hope and joined the huge queue of several hundred desperate hackers. (Thanks, btw, to ScottyTM for pointing out that the "fast line" had been opened.) Finally, I was told that my ticket "did not exist in the system", that I was an evil cracker for trying to enter with a fake ticket, and that I should check back on the 27th. Great.
The end was happy and somewhat anticlimactic: I checked back this morning, there was no queue, and my presale ticket was accepted without any problem. Most of the talks I saw today were about network neutrality, censorship and related topics. I found the talk by Jérémy Zimmermann from La Quadrature du Net especially interesting. Part of the talk was an introduction to lobbying: calling your EuroParl representative, sending e-mails and insisting on your point "raises the political cost of certain decisions".