With the better ones having a code number needed for usage like the F770 this is a good deterrent, one of the reasons I wanted one without a screen, it doesn't look appealing imo, I don't think there is a particular market for stolen cams in uk, I used to hide my cam every night in glovebox, but the cheapest nextbase(not that I would recommend them)is around £40, so a fenced one will only get a druggie £3 or so, just not worth their risk and better still THEY realise this.
I see cars parked on my estate with sat navs on display all night every night and remain amazed they are still there as mentioned much more likely they break in after seeing other things, near to where I live is a massive USAF/E base the GI's ALWAYS leave laptops, games consoles, cameras, phones, handbags, wallets etc on show a lot don't lock their cars, my dads neighbour candy did the same leaving her geo prizm unlocked with her handbag next to the handbrake/e brake for hours in high street whilst shopping, a local area is known as the USA candy store, but it's not a shop!!, it's a car park in the woods where nature trails are not a week goes by without several hundreds worth of goods being stolen mostly from unlocked cars and on view, I'm not GI bashing but they do seem to have a misguided sense of safeness to do these things I have a lot of GI mates and some of them do it even after years here.
I always work on the premiss make your car LESS appealing than others close by and they will move on, though nothing is 100% certain these days.