The consumer gadgets that are multiplying around our bodies and homes are the vanguard in a spreading platform war between the biggest tech companies. but they also pose a challenge for their makers: how to fit more closely into everyday life without provoking a backlash.

The limits of googles ability to use hardware as the vehicle to extend the reach of its data-hungry advertising system was made clear by the news this week of concessions it is making to get eu approval to buy fitbit. among other things, the search company wont be able to make use of data collected through fitbit devices to power its ads for a decade.

This points not only to the restrictions google faces in using acquisitions to extend its reach, but also the growing regulatory resistance to its efforts to spread into new domains of users lives. data is the thing that breathes life into its gadgets, personalising experiences as well as supporting advertising and commerce. beset by growing political and regulatory concern that it is the champion of a new and invasive form of surveillance capitalism, google needs to tread carefully.

Contrast that with amazon. a week ago, the ecommerce giant thought nothing of showing off its first indoor drone, designed to patrol a home for intruders. lifting off from a docking station, the device is the first product of amazons push into smart home technology that can move under its own power the progenitor of the home robots to come.

Eric schmidt, googles former chief executive officer, once talked about the creepy line that defines the limits of consumer acceptance of powerful new personal technologies. googles aim, he said, was to go as far as it could without actually crossing the line. amazon, by contrast, seems to think nothing of leaping over and striding straight ahead.

One result is that surveillance is now almost part of the amazon brand, for better or worse. new product announcements such as the indoor drone often produce wry smiles and head-scratching from the tech crowd, not the outrage they might attract if another company had come up with the idea. and many consumers seem to welcome having orwellian-sounding technologies at their fingertips as anyone who has a neighbour addicted to the surveillance videos from a ring doorbell can attest.

Where other tech companies balk at pushing the boundaries of the acceptable, in fact, amazon ploughs ahead. as geoff blaber, an analyst at ccs insight, says, there is a risk of a backlash, but: at least theyre addressing the category, and learning.

Amazon also said last week that it was getting ready to launch a neighbourhood-wide wifi network (called sidewalk) that will ride on the back of all those echo speakers and ring doorbells in your vicinity, making it possible to track devices (and their owners) well beyond their own homes.

At heart, amazon is betting that it has permission from consumers to stretch the boundaries of what is acceptable in domestic surveillance. there is a clear risk that this will eventually provoke a privacy reckoning.

The difficulties google faces in making full use of its devices data-gathering capabilities, meanwhile, raise what has become a perennial question for the internet company: why do hardware at all?

This is something google has never fully answered. sales volumes of most of its products are low, and it has shied away from putting serious marketing and distribution investment behind them. this weeks announcement of googles latest slate of personal gadgets demonstrated the usual confounding mix: some impressive technology at attractive prices, but no sign that google is about to go all-in on hardware.

There are still reasons to keep trying. for google, a network of smart devices is a good way to infiltrate the home, embedding its artificial intelligenceinto the everyday experiences of users. hardware also plays the role of an expensive hedge against the risk that it will someday be less able to count on others to distribute its mobile services.

Will it ever need to make use of that hedge? antitrust pressure has been growing, and europe has already made an attempt to turn android into a more open platform. there is no sign yet that this is eating into googles mobile service revenue. but it makes it highly likely that, for google customers, gadgets will be part of the tech menu for years to come.