True, but the worst that would happen if someone did plug in high-powered power tools (more than about 1,300W) or a lawnmower is that the 5/6A fuse/breaker protecting the lighting circuit might blow/trip - that's what they're there for.
Kind Regards, John
On a dark night while the other half is handling a kettle full of boiling water you don't want to be plunged into darkness. (Yes, I realise one does not cut the grass at night, but you get the gist).