Ultra tiny mobile phones

Years ago I visited someone in prison and the searches on the way in were very thorough. Apparently there is a real issue with drugs and smuggled mobile phones. So, there is a ready market for mobiles phones that cannot be detected when hidden within the body.

Imagine my surprise when I could easily find such phones sold via Amazon! OK, I am sure some users just want a really tiny phone, but these are aimed, allegedly, at the illegal market in phones to be smuggled into prisons. Should these be banned?

See https://www.amazon.co.uk/J8-World-Smallest-Mobile-changer/dp/B00O586YB2/ref=pd_sim_107_4?_encoding=UTF8&psc=1&refRID=0HQM62NG9CBSKACSHZMN