A little Mardi Gras irrelvantness.
If this is annoying in Europe, think about Venezuela where it happens constantly...
.. no matter how politely people are asked before to shut up their cell phones. They just do not. In movies I have gotten into fights as people truly cannot understand why I object them taking their calls during the movie.
The other pet peeve of mine that really turns my stomach are the jerks in the US that stand up at the Hallelujah during performances of Handel's Messiah. Of course, in Venezuela some assholes are trying to bring this idiotic custom here.... So I have not attended a Messiah anymore. But one day while travelling in the US if I can attend one Messiah I will stand up at a random aria and let people wonder WTF.