BERLIN, Dec. 27 (Xinhua) -- The annual Chaos Communication Congress, one of the largest European hacker conventions, started in the German city of Leipzig on Thursday. A record number of almost 16,000 visitors are expected at this year's convention.

It is organized by German hacker association Chaos Computer Club (CCC) for the 35th time.

Frank Rieger, press spokesman of the Chaos Computer Club, told Xinhua on Thursday that the large number of visitors at the convention "shows the importance of the critical debate on topics such as surveillance, social media, stalking, but also the distribution of power by digital tools".

The topics of this year's congress, which is called 35C3, range from Smart Home applications to artistic abilities of robots. "It is important for us to have a broad spectrum of opinions at the congress," said Rieger.

Today's global communication would also be a big topic, according to Rieger. What advantages as well as disadvantages could arise when "all people in the world are suddenly able to communicate with each other", Rieger added.

Political topics will be discussed as well at the congress, such as new police laws in Germany, which grant police forces far-reaching rights in law enforcement and surveillance. Back in May, the introduction of a stricter police law in the German federal state of Bavaria was subject to widespread protest.

The 35C3 congress takes place under the motto "Refreshing Memories". Among other things, this year's congress would be about reflecting on what "was good and what was bad in the past of the Chaos Computer Club and, above all, what have we achieved so far," Rieger emphasized.