[4][5] The JonDonym client program allows the user to choose among several Mix Cascades (i.e. a group of anonymization proxies) offered by independent organisations.

However, it means that all the relays used for JonDonym-mediated connections are known and identified, and therefore potentially targeted very easily by hackers, governmental agencies or lobbying groups.

Jondos GmbH has taken over development and continues to work on an improved blocking resistance function that would make it easier for users from restrictive countries to get a connection to the system[citation needed].

As contractors of Jondos GmbH must ensure sufficient throughput of their mixes, anonymous web browsing at speeds 30-50 kbit/s is possible.

In July 2003, the German BKA[8][9] obtained a warrant to force the Dresden Mix operators to log access to a specific web address, which was hosting child pornography.

The feature was made transparent by publishing the changed source code on August 18, 2003, and subsequently criticized by many users.

Tracing activities back in the past is still technically not possible for the operators, but anonymity now extends only to the time-point that a surveillance court order is issued.