I am pretty strict on differentiating the capitailized and non-capitalized versions of the word *internet. An internet is simply a connection between two networks. When talking about the loosely-connected network of networks that spans the globe, I always capitalize it. For most purposes, I suppose, the reader will generally know which 'net is being discussed. But the tech gurus (who really run the world) need to have ways to differentiate.

JMHO