Its only 'bulletproof' in PR and Ad copy, because for as long as the US is capable of undermining any tech company that operates within its purview with NSL's, the 'perception of security' is a total fallacy.

In other words, the technology is not bulletproof, no matter how hard the marketing people work to make it appear so - only the society within which the provider operates can provide that safety.

For some, this is an intolerable state of affairs - for others, perfectly tolerable.