Following complaints from players during the 2006 British Open in Hoylake, organisers of this year's event at Carnoustie will be banned from taking their mobile phones on to the course.
Director of Championships for the Royal & Ancient organisers said, "We have so far resisted the call to ban mobile phones on the grounds that it may be an inconvenience to the public. However, after receiving complaints referring to the numbers that were in use as play was proceeding, we feel there is no other reasonable option than a complete ban."
Security checks will be carried out on spectators upon entry. Presumably the public aren't trusted to keep their mobile phones switched off, so they have to be banned completely.