[craigsmansion]

It's a point that causes a lot of confusion.

As soon as a piece of software is replaceable, the one who provides you with the software can use its distribution to make you promise to ignore the four software freedoms.

If a piece of software is not replaceable, that point is moot, since the one who provided you with the software has no sway over you regardless. They have no control over you or the device.

[Yetanfou]

Better rephrase that to indicate that they have no more control over you or the device than the non-replaceable firmware allows, this is definitely not the same as "no control". Non-replaceable firmware can ping home, it can be used to monitor users, it can download arbitrary code and run it, it can listen for some trigger to start messing with your data or downright destroy said data, it can start randomly rebooting systems or non-randomly restart all affected systems at a specific time - which may cause brown- or blackouts depending on the power draw and -supply, etcetera.