Wikipedia on a tale about one Hippasus of Metapontum,
who supposedly was drowned by Pythagoreans for his
discovery of irrational numbers and/or of the dodecahedron —
"In the hands of modern writers this combination of vague
ancient reports and modern guesswork has sometimes
evolved into a much more emphatic and colourful tale."
See, for instance, a tale told by the late Carl Sagan,
who was bitterly anti-Pythagorean (and anti-Platonic):
For a related colorful tale, see "Patrick Blackburn" in this journal.