Yeah, that's another thing I never really got. Tatooine doesn't exactly have a dense population, and the spice isn't being mined on the planet (presumably), so why is it such a big deal for them that they NEED the spice to be transported planet-side? Why were they transporting it through Tusken territory anyway? Certainly they'd just be setting down in the biggest star-port, selling the spice to the local dealers to distribute, then heading back up? Hell, what product or services are all of these local gangs supplying/pushing, anyway? If you're a crime lord and all you do is control and administer your local area, then you're just the local authorities.