[The Logo is available in a vector format.]
[Alexander wrote in German; this is a rough translation:]
The logo depicts a Gnu in frontal view as well as a dove carrying a key. To me the the bird fits well as a symbol for freedom (see also: carrier pigeon). The wings of the dove also represent the ears of the Gnu, the body as the nose's back. The key is the muzzle and connects everything to a unit.
I thought of a putting the entire logo onto a background. I played with a star (sheriff's star) put replaced it by something which resembles a safe's lock. This might need to be thought again.