Euro 2012 players warned off Twitter
Teams fear that off the cuff remarks on Twitter could cause problems during this month's finals in Ukraine and Poland and other sides could follow the directives.
England captain Steven Gerrard told a news conference on Friday: "We've been told not to be tweeting anything unnecessary."
Spain midfielder Cesc Fabregas earlier tweeted: "From today we are not allowed to use social networks, I wish that the next picture I post will be with the Euro Cup. See you soon!"