The elderly and vulnerable most likely. Over here we have any number of consumer advice programmes (e.g. Watchdog) highlighting ridiculous scams such as this, yet people do still fall foul of them.

On the other hand, one of the worst scams presently around in the UK is the one sponsored by the HSE (Health and Safety Executive) whereby they have deliberately misrepresented white asbestos as being as dangerous as blue and brown. Unscrupulous contractors have latched on to this and are charging industry, commerce, and the general public thousands of pounds for "decontamination work" that simply doesn't need to be done. No wonder they don't like this site.