I thought Jo Brand’s battery acid joke was quite funny. But not harmful. It’s unlikely to inspire a revival in British Leyland’s business and anyway the burny stuff is quite hard to get hold of. At least, I assume so. I’m not a hundred per cent sure of that, because I know that if I look up ‘battery acid for sale as a weapon’ online I’m likely to have contravened some anti-terrorism law or other and will end up spending…