[gruez]

I think the point is that the company keeps the data around forever when they only need for a few months after the trip, at most.

[tomp]

When I was applying for UK citizenship, they needed 5 years of all travel data (entry and exit into the UK). EasyJet's databases (and other flight providers') provided useful. Of course, you could wonder why the government even needs this data, or why they don't keep it themselves (I don't for a moment believe that UK government / spy agencies doesn't have all data about all flights in and out of the UK).