This is a valid point. In EBL tournaments, mobile phones used to be forbidden in the playing area. Lately however (since 2012 or so), you were allowed to bring them but they needed to be switched off.
Imo, smart watches will be a bigger problem, and to the best of ...
Kit, you got board 17 wrong. The right layout can be found under http://www.eurobridge.org/repository/competitions/14Opatija/microsite/Asp/BoardAcross.asp?qboard=017.26..1020.
Makes more sense like this and the heart signal makes even more sense.