Oh yes it's easily circumnavigated, but it all depends on how far you want to audit, i.e. checking the site for the part supposedly installed etc. Tyco used to have an investigation dept that looked at things like theft and fraud.
They could if they wanted, they could also audit parts as every part booked out (excluding consumables) has to be attributed to a contract number.
In the grand scheme of things it's not seen as an issue.
I've not had a personal phone since the 90's but do have expensive 'work' phones the latest costing c£800 and I've just ordered a TV for a similar amount, have a look around your home and as most I'm sure it won't take long to tally up a fair few K.
The main thing I chose to protect is the family, having said that I guess the plus side of any break in would be the knowledge I'd saved a few hunred squid...
Cheers, it's for the Mrs, she flosses all the time so I'll have to think of something else for her Christmas...
Eta she's from a family who look like the Colgate family and neither her, her sister or father have a single filling (I think her mother has a couple)
Ding! on a forum I frequent someone has just posted a photo of 2 x 69 plate cars (x5 and an full fat AMG Merc) with a pic of his cluster sat nav display showing his home location, a quick google shows no bellbox (back in 2016)
tbf the smash/melt and grab and keyless scroates don't care but at least make it a bit difficult for them.