There's nothing particularly unusual about unruly behaviour on public transport - which is what a low-cost flying is. Such disturbances are so common on trains, and to some extent on buses, that they are rarely reported, and the history of them goes back as far as the history of public transport. What is happening now is not that people are becoming more unruly - there have always been unruly people - but that flying has become so common that the incidences appear to be greater. Statistically - and I have no figures to prove it - I suspect that nothing much has changed.