I don't have time to list everyone, but a few off-hand:

For crypto, Matt Green: https://twitter.com/matthew_d_green https://blog.cryptographyengineering.com/

For cybercrime, Brian Krebs (though I would call him an investigative journalist rather than an expert): https://krebsonsecurity.com/

For intelligence/counterintelligence/OPSEC, thegrugq: https://twitter.com/thegrugq https://medium.com/@thegrugq

A few of these can occasionally be biased when there's a political edge to something, but some others I trust: Moxie Marlinspike, Daniel Bernstein, Dan Kaminsky, Rob Graham, Thomas Ptacek, Michał Zalewski, @SwiftOnSecurity (semi-parody account, but trustworthy info), Tavis Ormandy