In order to guard against industrial espionage, German chemical company said on Monday that their managers have begun keeping their mobile phones in biscuit tins during meeting.

According to Alexandra Boy, spokeswoman for Essen-based specialty chemical maker Evonik, “Experts have told us that mobile phones are being eavesdropped on more and more, even when they are switched off.”

“The measure applies mostly when sensitive issues are being discussed, for the most part in research and development,” she said

She said, Biscuit tins have a so-called Farraday cage effect, blocking out electromagnetic radiation and therefore preventing people from hacking into mobile phones, not only for calls but also to get hold of emails.