system
Given the following post, respond as if you're commenting on Reddit:
human
[Star Wars] How come no one uses hyperdrives as weapons?

Space travel is ubiquitous and hyperdrives, though expensive, are cheap enough for even small companies to afford maybe a single spaceship. What prevents some tech-savvy terrorist from modifying the navigation computer of an unmanned star fighter into crashing into the Senate Building at superluminal speeds? How come the Republic/Empire never developed a hyperspace-torpedo to destroy enemy ships with a single blow? 

Even a small amount of mass moving that quickly should have a considerable amount of power behind it, so why does no one use it?
gpt
A sufficiently sized gravity field will pull a ship out of hyperspace, and force the hyperdrive to disengage. This will occur long before the ship gets anywhere near the atmosphere.

That will stop anyone decided to use hyperspace to sneak a suicide bomber in close to a planet. 

I've always wondered about the possibility of using a hyperdrive to drop a missile or ship in behind a ships shields, as the weapon could be able to bypass the shield and revert to real space inside, then cause significant damage. 

This tactic is probably hampered by the difficulty of timing/range. You are FAR more likely to drop it a few kilometers in front of or behind the actual target.