What do hard-core computer hackers and technology freaks do when they get together in a big horde? The place to find out is Leipzig, and the time is now. That's because CCC is holding its 34th annual meeting there, from December 27 to 30, under the rubric "Do Something."

Read more: Russian hackers stole US secrets from NSA

Around 15,000 people are expected to take part in the sold-out event, some 3,000 more than last year. For Germany's dedicated white-hat hackers and computer nerds, it's the biggest, best festival of the year.

"We're delighted with [the event's] popularity and the enthusiasm with which people come to us," CCC spokesman Linus Neumann said.

CCC is concerned with freedom of information, privacy, digital technologies, experimentation, and digital arts, culture and politics, among other things. The association's subculture is imbued with more than a hint of anarchist techno-Utopianism — that's why the word "Chaos" features in the title. Given that this is Germany, however, the event itself is, of course, anything but chaotic. It's relentlessly well-organised.

Featured activities and themes

Some of the people who participate in CCC's annual congresses engage in classic white-hat hacker stunts like probing computer vote-counting systems for vulnerabilities and then gleefully announcing the results if they find something tasty. But only a minority of CCC aficionados engages in that sort of thing. The spectrum of events goes way beyond network security. 

The annual Congress comprises talks, specialist assemblies, hackathons ("challenges"), displays, discussions, and loads of shop-talk. Most of the formal presentations are simultaneously translated, German-to-English or English-to-German.

The event's online Call for Participation sets out the agenda: "During four days between Christmas and New Year's, thousands of hackers, technology freaks, artists, and utopians get together... to communicate, learn from each other, and party together. We focus on topics such as information technology, networks, digital security, making and breaking. We engage in creative, skeptical discourse on the interaction between technology and society."

The Congress is organised into six "tracks," entitled Arts & Culture; Ethics, Society & Politics; Hardware & Making; Security; Science; and Resilience. The latter is optimistically described in the Call for Proposals: "In the Resilience track, all submissions are welcome that lead to a world more worthy of living in — be they long-running projects or recent developments." Vague as this sounds, it's a marker of CCC's let's-make-the-world-better anarcho-activist ethos. 

There's a lot more to the Congress than formal talks by experts on computer security topics — though there are plenty of those. As the prospectus puts it:

"Apart from the official conference program, the Chaos Communication Congress also offers space for community assemblies, developer and project meetings, art installations, lightning talks, and workshops. We also have special places for kids to learn and tinker."

"Community assemblies," in the special jargon of CCC, are places in the trade-fair halls where communities interested in a particular special interest can meet and groove together. "Assemblies play a huge part in creating the special 'Congress atmosphere'." the prospectus says.

"Lightning talks" are five-minute presentations. A wide diversity of topics is welcome  these can be well-prepared expositions of an idea or project, or simply "rants."

History: CCC's roots go way back

CCC's website says the club has over 5,500 members, making it the biggest hacker club in Europe. It is composed of 25 regional "Erfa Circles," which are local chapters of the club, most of them located in Germany's larger urban centers.

CCC was founded as a not-for-profit registered association way back in April 1986. Its founders were people who recognised the potential inherent in the then-new phenomenon of networked computers. They had begun publishing a hacker magazine called "Datenschleuder" (data slingshot) in 1984, the same year they first held a big annual meeting in Hamburg. Self-described "Komputerfrieks" who went on to participate in CCC's emergence had been meeting in Berlin occasionally even before that, starting in 1981.

From these beginnings, it developed that every year between Christmas and New Year's Eve, CCC has organised what is, in essence, a trade fair for hackers, the "Chaos Communication Congress." Every year, the Congress has had a different motto: "A New Dawn" (2014), "Gated Communities" (2015), "Works For Me" (2016), and now "Do Something."

In most years, the Congress has been held in Hamburg or Berlin. In 2017, for the first time, it is being held in the increasingly hip city of Leipzig, 200 km south-southwest of Berlin.

It's too late to get tickets this year - the event is sold out. But if you're in Europe next year (2018) between Christmas and New Year's, and techno-nerdy white-hat hacking, maker fairs, and digital freedom are your cup of tea, you might like to consider attending. Just make sure you grab a ticket in plenty of time.