I'm not a lawyer, so I will admit that your point may very well be valid.

But, if it is valid, it seems to make no sense. FT-ers bash United Airlines all the time on these forums... how come no one gets sued?

What's the difference? Why is FT liable for lawsuits in the case of an individual and not in the case of defaming a company (assuming that whatever is said in these forums is the truth, not false accusations)?