After the Unification, research and development on artificial intelligence stalled. At first it was because the prevailing cultural philosophy was that humankind had to pull itself out of the muck instead of relying on robots to do all the work for them. Later it was worries that developing too-intelligent machines to do everything would be slavery, so best to avoid creating AIs at all.
Linktech is technology that enables a user to control a machine as if he were controlling his own body. The technology is still fairly uncommon, as the operation is expensive and not everyone is comfortable with having a USB port inserted into their spinal cord.
Linkdrones are any machine remotely operated by a linktech user.
The technology is mostly used for jobs too dangerous for a human but requiring more independant thought than a non-intelligent robot has. Mining, deep sea or volcanic research, and exploration of planets too deadly for even an environmental suit are common uses of linkdrones. Linkdrones were used in the space battles of the Yogzarthu War, basically sending winged guns at the enemy instead of risking an entire fighter craft and a pilot. Linktech is also used for a type of art where the user links into a program that allows him to record his thoughts. It is considered either the purest form of art or cheating, depending on the critic.
The operation inserts a port into the spinal cord, partway down the back of the neck. The port is covered unless the user is linked.
Each linkdrone is equipped with a key - the key is the part the user plugs into his port. It is possible to create a master key to control several linkdrones, either seperately or, very rarely, all at once. It is possible to hack a linkdrone so a user can control it without the proper key. Hacking a key does nothing - one cannot take over the body of a user through their key.
Learning to use the link takes work - controlling a linkdrone is like having a second body while your regular body is still active. Even once used to a link, there is still a sharp learning curve for any new linkdrone - a bulldozer operates differently from a camera, after all.
Linkdrone shared senses vary, though almost all provide visual, audile, and tactile feedback to the user. Often the audile and tactile senses will be dulled, if the work is too noisy or hard, but complete lack of such feedback makes it far more difficult to interact with the linkdrone's environment. Between the perceived physical and real mental strain, controlling a linkdrone is tiring work.
It is possible to die in link. The risk is greatest for new users - if the linkdrone is destroyed, the user may die of shock if he is unable to consciously seperate the experience of the linkdrone from his own. Other times a user may be so caught up in living through his linkdrone that he forgets to tend his organic body.