Consider the following two offers:

A cheap netbook from a no-name Chinese OEM, running weird software you've never heard of named 'TAILS' which doesn't auto-update or anything, and which the makers say is very secure.

A cheap phone from a no-name Chinese OEM, running weird software you've never heard of named 'Sky ECC' which doesn't auto-update or anything, and which the makers say is very secure.

You've got to be fairly knowledgeable to appraise the two options correctly.

Sky ECC over TAILS it is!