On social media the new religion is sharing. Some of that sharing may not be very nice

One of my birthday presents is a pair of rubber stamps, one with a thumbs up ("Like") and one with a thumbs down ("Dislike"). So I can now rubber-stamp the world to rights. I wish Facebook and Twitter had Dislike buttons but they don't. Disliking someone's dog would, I suppose, ruin a perfectly good virtual friendship.

While we are told that social media makes the world incredibly complicated, much online discussion is very simplistic. I say this as an avid user of the technology that enables my narcissism as much as yours. There is joy to be had, but much online behaviour needs to be questioned.

Around the John Terry case, the default mode was to slag off Terry to prove one's anti-racist credentials. Something about this is nauseating but then in many recent discussions about racism I find myself on the "wrong" side. I don't think the Terry case should ever have gone to court. I don't see why calling someone a cunt is perfectly acceptable when I keep being told off for swearing.

The question of context is missing. Again, I read Mehdi Hasan on being abused for being a Muslim. Of course I don't think it's right but he uses terms that not all of us accept in the first place, such as "Islamophobia", which muddles faith, ethnicity and identity in unhelpful ways. Nor do I think Jonathan Freedland should be abused for being Jewish anymore than I should for being a woman.

How do we stand together against this? For much of this argument splinters back into identity politics. The terms "misogyny", "anti-semitism" and "homophobia" may be useful but too often are used to shut down rather than open up online debate. This is why free speech is so difficult. It may be that a certain level of abuse is the price we pay for it. Do we ban or "moderate" opinions we don't like? And who is going to monitor these anonymous haters? The unknown quantity is the interrelation of online personas with actions in the real world. Thus we defend someone who made a joke about blowing up an airport because we don't think he was really going to do it. Threats of sexual or racial violence we see as a different category.

Lately, though, I am becoming more and more uncomfortable at the nature of online interaction. Not only do I think there is more to being an anti-racist than a retweet, the cases of invasion of privacy that social media cheers on are nasty, petty and curtain-twitching. I am referring to the cases of drunk or ill people racially abusing others on public transport. Then last week we had a comedian live-tweeting a couple having a row on a train. Some people found this hilarious. The couple were named and photographed by this comedian/citizen journalist/spy. Is this funny in real life? As Leveson trundles on, is it now OK to turn oneself into a hacker/paparazzo for everyone else's entertainment?

The problem is that social media has no concept of privacy. If the couple were arguing in public, anyone may record and snigger at it. But this is to confuse public space with social space, for social media makes everything "social". That's how it works. "Social" is, as Biz Stone, founder of Twitter, said, "the killer app of the 21st century". Sharing is the new religion. And some of that sharing may well be not very nice. Much online abuse, for instance, would not occur face to face in public.

Andrew Keen's new book, Digital Vertigo: How Today's Online Social Revolution is Dividing, Diminishing and Disorientating Us, asks some awkward, important questions. If we live online and everything is "social", what is outside it? What is privacy? The move from a platform for data to a platform for real people is huge business. Freedom of expression boosted by entrepreneurial libertarians may have its cost. Keen talks of Michel Foucault's theory of the Panopticon, the late 18th-century model of building prisons so that all inmates are visible in separate rooms but, feeling watched, police themselves; it's "the trap of visibility", as Foucault called it. In the same way, the internet appears transparent, yet is monitored and mined for data; we are all potential consumers.

The internet is not the answer to loneliness or isolation, and many younger and older than me have little use for it. They would rather connect in real life. It is all too easy in the media to underestimate this reality or to understand how inactive many social media users remain.

To truly measure the psychological cost of the free apps of Twitter, Facebook, Pinterest and so on, would mean understanding the huge shift between public and private which neither the judiciary nor government appear to grasp. The missing element is exactly what may be deemed political because when everything becomes "social", the refiguring of what is public and what is private, what is collective and what is individual, means connecting how we act in real life with how we interact online. The danger is that technology may well make us feel we are doing something when we are not. But therein lies the profit. While we under-share in the real world, online we over-share like crazy. And call it freedom.