And sadly - if someone emails a PGP encrypted mail to a protommail address using a key the recipient knows but protonmail doesn't - it doesn't work. Protonmail gives an "unable to decrypt" error, and doesn't hand over the encrypted body...

For me - I think they're useful protecting against dragnet "full take" surveillance (especially since I'm a non-US citizen, so am considered "fair game" for warrantless surveillance), but I don't for a moment think they'll protect me from any sort of state actor level interest targeting me specifically (I'm still gonna get Mossad`ed upon...)

(In more paranoid moments, I suspect that the first "dragnet" protection quite probably makes the second "targeted interest in _me_" more likely...)