The discussion of the security of public wireless networks is way beyond the scope of this forum. As it began to heat up, may I ask you to take it somewhere where it is on-topic?
However, one advice: everyone using the Eurofurence WLAN network should keep in mind that it is a public network, regardless any link layer security it may implement. It is the user's responsibility to take the appropriate steps for secure transport layer authentication and encryption, especially when highly sensible data is involved. Also note that this requires a correct setup at the remote side, which is usually beyond the influence of the user.