Wow, I could write a book about this question
Actually I did
It was the subject of my dissertation not so long ago.
The major concern I had, and still have, is how Facebook and other social networking sites basically remove any remaining threads of privacy that we have left today. I considered this to be 100% the fault of the person who created it.
We have an interesting situation here in the UK. I think there may have been some similar cases in the USA and others, but I didn't really consider these as they weren't appropriate for my argument. Once upon a time, if you applied for a job, you were invited to an interview, possibly involving a recruitment event where a number of potential employees were 'put against' each other while members of that particular company observed. A decision was based on whether they liked what they saw.
Nowadays, before you are even considered for an interview, someone will Google you. If they find a profile of you, it is read with great interest. And it only takes a single 'bad' photo, or comment, even perhaps something listed in the 'about you' section, for the employer to discard your application. Facebook even had an 'agreement' shall we say with certain companies, so that they were able to view profiles of anyone. It went against their privacy policy for a start. And oh boy, the response I got when I challenged their Press Office about this was utterly priceless
I really do think if they were able to trace me they would have sent someone around straight away (the Mafia possibly
) It was something hardly anyone knew about. I don't believe they still have this arrangement, but let's face it, many teenagers are naive enough to accept anyone and everyone as their friend, irrespective of whether they know them or not, so gaining access under an alias really isn't all that difficult.
The USA has a kind of privacy law (embedded in the Constitution and the [Fourth?] Amendment). In the UK, we do not. We have privacy
policies which the Data Protection Act enforced, but there is no actual privacy law. Many falsely believe we do have one, which was created by the European Convention on Human Rights and became law under section eight of the Human Rights Act. But how wrong they are! Having 'respect for one's private life' holds absolutely no weight at all.
We have likewise had a number of situations where people have been sacked from work because of something they posted on their profile. Fair enough, some have been comments defaming the company they work for: others have simply said 'I hate my job.' Personally, I don't know what's more frightening. The fact that this new form of communication has revolutionised how we go about our daily lives - and not necessarily in a positive way - or that there are people out there observing everything we are doing.
I'm not suggesting we are living in a Big Brother society, as Orwell predicted. But over 200 years ago, Bentham devised the Panopticon. Expanded by Foucault, the theory is that we only need to believe we are being watched for the same effects to materialise. Back then, it was used to devise a more suitable prison service. Therefore, perhaps we are now prisoners of our own society.
And that is my very long and somewhat complicated reasoning for why I will never have a Facebook account