Trends: Cell phone tracking
More and more, people use GPS to know where they are. The problem, however, is that law enforcement, marketing firms, and government agencies are more and more relying on cell phone tracking. The most surprising part to many people, is that you don't even need a GPS device to be tracked, all cell phones can be tracked by your provider. Your phone connects to cell towers, and it's trivial for your provider to know which tower you're connected to, and how strong your signal is, thus knowing where you are within a few meters.
While bringing criminals in because of cell phone tracking is obviously a good thing, once the cat is out of the bag, there is no bringing it back in. For example, Missouri allowed private companies to track users to monitor traffic conditions. What would you say if you went near a billboard with your bluetooth enabled phone, and the billboard would connect to your phone, customize ads for you, and beam them right to you. It's already happening in some parts of the UK. Plus there's all the privacy concerns of having people know where you were at a precise moment. Unfortunatly, all this is available to all providers without you being able to do anything about it, and the only solution resides in having decent laws.