Comedian Chris Rock's foul-mouthed appearance at Live Earth London prompted TV host Jonathan Ross to apologise to viewers.
And when Stewart played at Rioch Arena in Coventry, England on Tuesday (10Jul07), he promised to pay GBP10 ($20) to each member of the crowd if he swore.
He says, "I listened to people effing and blinding during the Live Earth Concert last weekend and it just sounded so cheap.
"If you hear me swear on stage I'll give you all a tenner."
Source: WENN