Weird that some disgruntled search engineer never leaks our some juicy bit of algo gossip, or lets something slip in the pub when talking to the wrong people. Happens in politics all the time. Maybe they are threatened with a NDA that would ruin them beyond repair.
If anyone is in Boston get on of them totally smashed and get them to reveal all.
oops wanted to edit the badly spelled title but cannot :)
Have you seen the film "The Fly" with Jeff Goldblum? He builds a teleportation device, he buys all the pieces from different places and all the engineers who make its components dont know how their component relates to another because they dont of the others existence or even what its for.
Perhaps this is what its like at Google, someone writes one part of the algo without knowing whos writing another, or even where/how/if it is going to be used. That way only teeny weeny bits of info can ever be revealed. Thus limiting any damage from leakages.
Only a select few will know the whole or even large parts of the algo.