A hackish form of silliness similar to Bi Capitalization for trademarks, but applied randomly and to arbitrary text rather than to trademarks. This is used very commonly on wiki sites. ThE oRigiN and SigNificaNce of thIs pRacTicE iS oBscuRe.
(This has been completely ripped off (with one sentence added) from . I apologize, and I will try to paraphrase it soon.)