[mcphilip]

OP's misunderstanding of prop trading vs funds aside, I still think it can be argued that "HFT in its worst form amounts to high speed computerized rumor mongering".

For instance, take a look at the Nanex article What is the Bid/Ask spread of this stock? [1]. Rumor mongering in this case being gaming the weakness of the NBBO.

On a side note, I highly recommend reading through Nanex's Strange Days research section if HFT related market anomalies interests you at all [2].

[1]http://www.nanex.net/Research/bloodbot/bloodbot.html [2]http://www.nanex.net/FlashCrash/FlashCrashAnalysis.html