But on the web every day one sees the kind of comment that no newspaper or magazine hack would get past the in-house lawyer unchallenged.
An explanation for this uneven treatment was voiced by a fellow speaker at an internet conference last week in Poland. He said the reason you can say what you like on the web is that no-one takes it seriously.
There is something in this but I don't think it is quite right. The astonishing thing about the internet is not that no-one takes it seriously, but how little of it sticks. Even the few things that go viral are largely forgotten within a few days. People spend hours online but each day they empty their brains and start afresh.
This seems to me to have interesting implications for the PR function in companies and whether they should respond to what is being said about them out there. Every day there is a conference somewhere advising how to track social media. But there are more than 145 million Twitter accounts, 500 million Facebook users and more than 200 million bloggers.
The bigger point is whether it is worth it. Companies get vexed about bad publicity and seem tempted to engage with every blogger. But if they do, they are not going to win the argument because it is unlikely to be rational. Indeed, it could be counterproductive because the more they engage, the more likely it is the attacks will become more widespread and abusive. It's a bit like trying to intervene to bring some sanity or accuracy to an argument in a pub. Neither party will thank you.
Of course people will say that while no company cares much about what is said about it in a local pub, it has to care if a million people can listen to that argument on the web. But is that really true? A million people may listen but if they have forgotten what they heard by the next day, can't the company simply ignore it? Without wishing to kill off a golden goose for the comms industry, the case for engagement is nowhere near as clear cut as widely assumed.
Anthony Hilton is City commentator on London's Evening Standard