The Borg have a hive society, known as the Collective, which seeks to perfect itself by absorbing entire races to gain their knowledge, technology, and abilities. This generally does not go over well with said races, but as Borg drones never seem to tire from announcing, resistance is (usually) futile. They are extremely adaptable and dangerous in combat. Whatever information the Borg assimilate spreads instantaneously to the entire Collective.
Much more information about the Borg can be found at Memory Alpha.
The Borg and the PPC
Because of their habit of assimilating technology and people against their will, the assimilation of even one agent or staff member is a multiverse emergency. Headquarters has a Borg Alarm, a tri-tonal klaxon that sounds whenever anyone in the know about the PPC is assimilated. It also supplies coordinates to Upstairs, so that the rescue and neuralyzation can get done ASAP.
The following agents were assimilated and subsequently freed from the Collective during the Assimilation Crisis:
- Agent Behnashiren
- Agent Canta Enquëo
- Agent Five of Six
- Agent Gareth
- Intern Hul Choka
- Nurse Nathonea Dewstan
- Agent Stoneship Tayrime
- Agent Tawaki Penguin
Agent Cyba Zero became one of the Borg due to a disguise generator accident, but her mind has never been part of the Collective. This has left her somewhat inept at using her cybernetic implants. The same applies to Sigma One and Phi Six, Cyba's two clones spawned by a misspelling during a mission.