Gonna start off by saying that, while I do find 'Star Trek' enjoyable, I'm not really into 'Star Trek'. With that in mind, I'll probably get some of the following terminology wrong. If so, it isn't done out of meanness, it is done innocently out of ignorance. Please don't threaten me with your phaser. 
Ok. On DS9, they have a collection of miniature shuttles. People from the station take a trip to a planet and all of them beam down. When they're done with whatever it was they went to do, they hit those little radio buttons on their uniforms and the shuttle's on-board computer beams them back up. But when people are on the station (or a ship) and they need to beam in or out, there's always a human operating the transporter control gizmo.
Question: If the computer on a mini-shuttle can beam people around, what can't the (obviously) much more powerful computers on a ship or a station do the same thing without human intervention?
Boru

Ok. On DS9, they have a collection of miniature shuttles. People from the station take a trip to a planet and all of them beam down. When they're done with whatever it was they went to do, they hit those little radio buttons on their uniforms and the shuttle's on-board computer beams them back up. But when people are on the station (or a ship) and they need to beam in or out, there's always a human operating the transporter control gizmo.
Question: If the computer on a mini-shuttle can beam people around, what can't the (obviously) much more powerful computers on a ship or a station do the same thing without human intervention?
Boru
‘I can’t be having with this.’ - Esmeralda Weatherwax