FSFE accuses AVM of GPL violations
In a legal dispute that began in January 2010, AVM has been trying to prevent Cybits AG from modifying AVM's Linux-based Fritzbox firmware. Cybits' "Surf-Sitter DSL" filter software downloads the Fritzbox software onto the user's computer, modifies it, and then reinstalls it on the Fritzbox. Harald Welte, supported by the Free Software Foundation Europe, is intervening in the case. Matthias Kirschner, FSFE's German Coordinator, calls AVM's actions an attack "on the very foundations of Free Software".
In January 2010, AVM filed for an injunction to stop the software from being distributed; this was granted by the court. Cybits appealed against the injunction and brought Harald Welte on board as an intervener (roughly equivalent to US Intervention law). The founder of gpl-violations.org had become interested in the case because both AVM and Cybits use the Linux kernel with iptables/netfilter, for which Welte holds intellectual property rights. Welte considers AVM's attempt to prevent third parties from distributing the modified firmware as a violation of the GPL, and therefore of his intellectual property rights.
AVM demanded that Cybits stop distributing or running Surf-Sitter-DSL, if "the software is used to modify, or modify parts of, the firmware embedded in the DSL routers manufactured and distributed by the complainant [AVM], in particular in the FRITZ!Box Fon [...], and if parts of said firmware are then reused along with unmodified parts". However, the GPL stipulates that anyone may use, modify, and then redistribute the modified version of software that is released under the GPL. The Berlin Court of Appeal subsequently lifted the firmware modification ban.
In addition to the injunction, which is only intended be a temporary solution to a legal dispute and during which no evidence is examined, AVM has also instituted principal proceedings against Cybits. The oral proceedings for this are due to take place at Berlin regional court tomorrow (21 June) and Harald Welte has submitted to be an intervener in these principal proceedings.