Dangerously strong magnets

Mark Allen is selling "dangerously strong" magnets for $5 a throw:

These are neodymium rare earth magnets with a magnetic field strength in the 45MGOe range. 45MGOe! I'm not kidding around here! Should two become co-joined by mishap, they are very very difficult to pull asunder. These magnets will fly eagerly through the air to reach each other, possibly crushing your fingers in the process. Let us be honest with each other- I'm simply not responsible enough to have these around.

Link (via Torrez)