Apparently this afternoon a TAP Portugal jet en route to Copenhagen has been intercepted by NATO fighters after several attempts at communication failed miserably.
De Volkskrant - Duitse straaljagers onderscheppen vliegtuig
Following the intercept, the airliner was allowed to proceed to its intended destination.
According to a spokesman at Eurocontrol, it is not clear what caused the 'communications breakdown': "Maybe the pilots had other things to do..."