I was a flying instructor at Luton Flight Training at the time, and the blockwork had LIA (Luton International Airport) inset in a darker colour. We all wondered for whose benefit this was, as the only people that would ever see it were pilots, and one presumes they all knew they were just about to caress Luton's tarmac, and not someone elses. The blockwork was removed very shortly thereafter and was dumped behind the fire station, and free to take away. At least one person I know retrieved enough of them to re-pave his driveway - he was a student pilot at LFT.
IIRC, Monarch tried to sue the council, but were shown the small print on the conditions and terms of use of the airport, which basically said tough luck. Probably apocryphal though.