I know that. But the article stated that that one particular cache was not cleared despite specific user settings/instructions to do so. It claimed that cache would retain its contents (and growing) while leaving its owner in the belief that they had cleared it. Thus inducing a false sense of security.
Anyway, the article has now been pulled, it seems, which could indeed indicate that it was left wanting. But doesn't necessarily!
Call me paranoid, but I'll be...