Fingerprint sensors and proximity-based unlocking do not protect your information.
The Courts have ruled that 1st amendment does not prevent a police officer from unlocking your phone by physically forcing your finger against the sensor.
Also, if you are concerned about privacy from governmental actors, you should not use cloud storage unless you have wrapped your files in an encrypted container (encrypting file names as well as contents).
The only thing that really protects you is strong crypto and long key phrases which are known only to you and which are independent of your OS's security (which cannot be assumed to to have no back doors and which necessarily caches your key where it can be harvested.) You should have at least 2 such phrases:
* one you use for things accessed frequently enough that you can't plausibly claim you have forgotten it -- which you use for lower-value data;
* one you use infrequently for high value content, which you can plausibly assert you have forgotten when forced to disclose it.
And since the presence of encrypted files itself causes suspicion, you should consider what you explanation will be, preferably using a deniable encryption system...but I'm getting off-topic.
The reason I mention this is to so that activists, and overseas travelers are not mislead by your article (which is otherwise is a good summary) into believing that their cellphone-based information is truly secure.
