© Hal Berghel 2014 . All rights reserved. All requests for reproduction and/or distribution of this electronic document should be submitted via Email to the author (hlb at berghel dot net).

This is a draft version (preprint) of material which was later published in substantially the same form in my Out-of-Band column in IEEE Computer. The published version is a copyrighted feature of IEEE Computer. All requests for reproduction and/or distribution of the published version should be directed to the IEEE Computer Society.