I know that some PPRuNers do not like this travel writer but I think this article is very good:
Simon Calder: EasyJet may have had a point when they threatened to ban the passenger that tweeted against them - Simon Calder - Travel - The Independent
While Mr Leiser had no ill intent, lesson one for anyone working in aviation is: a minor problem in the departure lounge can become a major incident at 30,000 feet.
Also, let's not forget that for ANY company established and running for 20 years, learning how to handle social media is just that - learning. Remember those folks who made joke bomb threat phone calls?