If you want to know whether someone is a genuine security expert, ask yourself: *whose* security are they arguing for?
If the answer isn't "the most vulnerable and disadvantaged party involved in the system", then you're not talking to a security expert, you're talking to a defense contractor.
@joepie91 if they defend google or facebook they are just defense contractors for a privatized state, the corporation.
(If you think "they aren't necessarily a defense contractor! what if they just argue for a company's security, like Google or Facebook?" then have a look at where they have worked before, and keep a look on where they end up working afterwards. You're going to find a defense contractor.)