[micro_softy]

"What's important is hackable by who, and in what way."

I strongly agree with this statement but my explanantion of it may be somewhat different.

Hackable means controllable.

Hack = control.

A computer, including a small form factor one called a "mobile phone", should be hackable by its user. Freedom to tinker.

A user can then, if so desired, set up and use the computer in such a way as to be less hackable by others. There is nothing more discouraging for an attacker than a highly idiosyncratic, non-standard system.

A user cannot protect a computer over which she does not have meaningful control. This is common sense. Mobile phones are just computers... with a lot of unneeded complexity. And third parties such as telecoms and search engine companies have greater control over them than users.

Trying to protect a user's computer by delegating control to a third party or combination of third parties, while denying control to the user, is an exercise in futility.

A computer that is sealed shut, with a locked bootloader and which can only use a narrow choice of OS, etc. is not hackable by its user.

It can be secured against users perhaps, but it cannot be secured in any meaningful way against third parties that truly benefits the user.

This is because the user does not have the most control over the computer.

It does not matter how much effort the user wants to make including how much money they are willing to spend in order to protect the computer because the user is not allowed to have as much control as various third parties.

A $5-$25 credit card-sized development board is easier to protect than a mobile phone.

Because it is "hackable" by it user.