One species that matters, S. calceatum, and it is the strongest candidate in the catalogue for an animal that should carry a warning rather than a description.
West African arboreal, feathered setae along the legs, extremely fast, defensive without needing provocation, and carrying venom among the most severe in the entire family. Documented bites produce systemic effects lasting days. There is no calm specimen.
It also breeds readily and sells for very little, and that combination is the actual problem. The price gives a buyer no signal about the risk, so beginners acquire it on cost and looks. If one genus page should be blunt rather than balanced, it is this one.