Kryptonite is protected by trademark law, at least

NY Lawyer: DC Comics' 'Kryptonite' Trademark Survives Court Challenge by Maker of Bicycle Locks

A federal judge has ruled that the owner of the Superman franchise, DC Comics, owns a valid trademark in "kryptonite" that can be protected from dilution and infringement by a bicycle lock company that adopted the name.

Southern District Judge Richard Owen issued several summary judgment rulings favorable to DC Comics in DC Comics v. Kryptonite Corp., 00 CV. 5562, including a finding that kryptonite, "Superman's one fatal flaw," is a protectable symbol under the Lanham Act.

The court did not dismiss a breach of contract claim about limited trademark use.

Related miscellany:
Kryptonite bicycle locks are vulnerable to ball-point pens.

Apple Corps. and Apple Computer are involved in litigation over a contract regulating limited trademark use.