Unusual sonos internet activity

I was doing some investigating on my monthly data usage and installed Princeton IoT Inspector to monitor what devises were sending out / consuming data.
One Sunday i noticed that all my 5 sonos speakers were sending multiple MBs of activity when nobody was home, no alarms were set and no speakers were playing. The really cool thing about the Princeton IoT Inspector app (MAC only for now...sorry) is that it told me where the data was being sent to, and how much data was being sent.
My sonos speakers were sending data to two locations just outside of Washington DC, in the state of Virginia.
I thought Sonos was a California company.
I live in Canada.

anybody know why?

There are a lot of datacenters outside of DC, near Dulles Airport. It's possible that Sonos is renting space there for their systems?

Sonos has locations in California, Massachussets, and overseas. In my business (games) the servers are almost never where the company is. We would either rent data center space directly, or more likely these days, use Amazon Web Services.

Locations mean almost nothing on the Internet, what were the domain names and IP addresses?

I assume that you were using an online music service during your monitoring session. As others have mentioned, online companies can use distributed servers, worldwide. This is done in an effort to speed delivery, balance loads, and provide redundancy in case of equipment or connectivity failures.

SONOS uses AWS for their cloud infrastructure. The biggest (and most popular) AWS region is the region out of Virginia. What's the IP address? I'm betting it will be an address belonging to AWS.

Sonos also use Azure for some of their work, and Azure is in more geos than AWS. This whole debate would be more useful if we could see the domain names/addresses that the OP is concerned about.