In order to create this 'targeted advertising,' they create huge databases of information on people. People called this creepy when the FBI was doing it, but it's ok when a private corporation does it? It's not like the FBI/CIA/MI6/etc doesn't just send a request to the company and get your data anyways... So I'm not really seeing the difference between any company having access to this information and the government having access to it.

In some cases, it may be that the government has better controls over who can internally access the data. Not that I necessarily trust the government to create such oversight, but the sheer amount of bureaucracy can prevent things from happening. On the other hand, there are plenty of companies that have 'organically' grown from a point were everyone was trusted, and now they have poor controls in place or they just have the bare minimum 'government mandated' controls in place to comply with the law.

In general though, I don't really think that anyone can be trusted with that sort of information.