Netgear has come up with a similar daft idea
Netgear now has a management mode which - I kid you not - overwrites the DEFAULT password of their devices. The moment you add a Netgear device to their "Insight" cloud it overwrites the password originally set in firmware and that would normally get restored on a full reset. That's only a great idea if it's covered under so many warnings and must-enable-first switches that it cannot be done by accident (I can see it have some function in making equipment theft pointless), but it seriously screws up any recycling of their gear because the passwords printed on the device become useless after such an "update" unless someone takes a careful note of the new setting.
What on Earth inspired them to do something this daft I don't know, but it's caught us out once. It sparked a general discussion about discontinuing the use of Netgear altogether, also because they also pretty much force you to register each device, but refuse to re-register a returned device/serial number* to a new customer, and quite a lot of their management modes demand access to geo location or flat out refuse to work which happens to conflict with privacy laws in so many ways we're of a mind to lob this over to the regulator and see if it creates some fireworks.
So, in summary, don't think it's just Sonos trying to pull a fast one. Netgear got there way earlier.
* Due to online purchasing laws which allow a purchase to be returned (in decent shape/state and working order) within 30 days.
Biting the hand that feeds IT
