"No new coal" was the the calling card of the mystery saboteur the Guardian describes as a 'green Banksy', who broke into a power station to protest about coal-fired electricity generation.
The Guardian controversially claimed the activist's actions "reduced UK climate change emissions by 2%", something virulently debated by readers and scientists.
Source: http://www.guardian.co.uk/environment/2008/dec/11/kingsnorth-green-banksy-saboteur
The £12m defences of the most heavily guarded power station in Britain were breached by a single person who, under the eyes of CCTV cameras, climbed two three-metre (10ft) razor-wired, electrified security fences, walked into the station and crashed a giant 500MW turbine before leaving a calling card reading "no new coal". He walked out the same way and hopped back over the fence.
The Guardian controversially claimed the activist's actions "reduced UK climate change emissions by 2%", something virulently debated by readers and scientists.
Source: http://www.guardian.co.uk/environment/2008/dec/11/kingsnorth-green-banksy-saboteur