OAKLAND — Cascades Computer Innovation, a nonpracticing entity descended from the original "patent troll," is back in federal court waging a legal assault against self-described troll-fighter RPX Corp.

In a novel case that tests the business model of defensive patent consortiums like RPX, Cascades saw its first complaint thrown out for relying on "generic" and "threadbare" assertions that RPX and several Android phone manufacturers engaged in an illegal boycott of its patents.