VSpike writes: "The Austinist reports on a classic misunderstanding reminiscent of the City of Tuttle vs. CentOS. A teacher sees a student showing off his HeliOS system and confiscates all the disks. She reprimands the student for distributing illegal software and then fires off a threatening email to the person who provided the software to the student, stating "No software is free and spreading that misconception is harmful.""
egrep patterns are full regular expressions; it uses a fast deterministic
algorithm that sometimes needs exponential space.
-- unix manuals