Facebook has always been very irresponsible in respecting people privacy and have done very bad things in the past in this matter.
Some time ago, according to Mark Zuckerberg (Facebook's CEO) declarations , I deleted my facebook account forever and I won't be back until it changes (thing I see very unlikely). Let's explain this and why facebook is evil.
- It is proved that facebook creates ghost profiles  and retains deleted data without the owner consentiment. This is specially true when deleting an account, or when using the "find your friends in facebook" feature, in which you type your email address and your password, and it search your possible friends in that social network.
- The friends of friends feature is totally wrong: If in real life friends of my friends could not be my friends, then why in facebook they act as if they were?
- Related to previous one, if I set my account to be seen only by my friends, then, when I post a comment, I like some photo of one of my friends, automatically, that content is available to be seen by uncommon friends, and the worst thing: My friend has to settle this privacy option for me!
- You explicitelly give permission to facebook in their TOS  to use without royalties any content you upload to facebook without an option to deny it. So if they want to use one of your personal pics for a cocacola's advertisement spot, then they use it, gain money with you, and you won't be able to complain (nor to see money).
- Many people are blaming google to index their name and last name because of facebook's account. This is not true. As a webmaster, I know that google respect your mechanisms to let it know to not crawl over some pages you may have. This way, I blame facebook because they simply don't want that to take place for pure economic interests (I remember all of you that facebook have a high page rank, and one of the reasons is having that much of data being indexed in google)
There are even more reasons to hate facebook's privacy idea, just because their CEO do not value their people's privacy, so I ask all my readers: Do you still want to be in a place where you are not valued?
Unfortunatelly in USA, privacy's law are not that strong than the ones we have in EU. For example in Spain, in which LOPD (Ley Orgánica de Protección de Datos, or Data Protection Act translated to english).
I am very pleased we have this law in Spain to ensure companies to treat my data correctly and to guarantee my rights. I explain it better, to allow you to understand why facebook can be considered illegal in Spain or in UE.
- LOPD says the data owner is not the company having the DB running, but instead, the data belongs to the owner the data refers to.
- You have some 4 undeniable rights:
- Access to ALL the data a company has about you.
- Alter any data to correct mistakes it can have.
- Permanent delete of partial or full data. Where permanent means that you can ask for it to be efectivelly deleted from their database, and not just be marked as invisible. What facebook does, they don't delete anything, just mark that data as invisible or something similar 
- You are granted to settle the visibility of your data even inside target's company. In other words, you can tell any company that it is forbidden to publish part (or all) your data even inside their webpage.
The conclusion would be: I am against facebook for those reasons, and I encourage people to stop using facebook or even to delete their accounts until they realize that we have privacy and my data is mine.