'Downton Abbey' cast gets Twitter warning from creator Julian Fellowes

downton-abbey-season-4-cast-Twitter-warning.jpgThe stars of "Downton Abbey" are apparently naughty social media users, as creator Julian Fellowes tells The Telegraph that he's had to warn them not to reveal too much from on set.

It all started because Season 5 guest star Richard E. Grant posted a photo of himself on Twitter in costume while filming. "He's very naughty," Fellowes says of Grant. "The trouble we've had with things like Twitter.

"We had to explain to the cast about the dangers of tweeting, as no one realized how interested everybody was in the show," Fellowes continues. "You're in a bubble when you're filming. You're just tweeting these nice things and you don't realize there are millions of people worldwide trying to pick up the plot."

Grant has been cast as Simon Bricker, a guest of the Granthams who visits the estate in Season 5 of "Downton Abbey," which returns in the fall 2014 in the U.K. and January 2015 in the U.S.
Photo/Video credit: PBS