The plant contains similar tropane alkaloids to the aptly named deadly nightshade (Atropa belladonna) namely atropine, hyoscine also known as scopolamine, and hyoscyamine. It is therefore a useful source of these medicinally used alkaloids for the pharmaceutical industry but nowadays is considered far too dangerous to be used in herbalism.
In 1910 it featured in the murder trial of Dr Crippen, as it was the source of the hyoscine that he used to kill his wife.
All parts of the plant are extremely poisonous.
A close up of the hairy leaves and flowers which I think are quite attractive but are often described as sinister looking. It is also said to have a noxious smell.