"privacy people often fall into this mindset that no surveillance is ever useful or proper."
They do? I haven't seen that. What I have seen is that privacy advocates often fall into the mindset that surveillance is frequently misused and that ubiquitous surveillance isn't proper. Which is true.
It's more likely that restaurant is IDing customers based on the WiFi beacons from their phones than face recognition (I say based purely on the fact that this has been common practice with larger companies for years now).
"ersonalized service is likely to boost customer satisfaction and create more visits."
Maybe, but personally I can guarantee that if I notice that a place is doing this sort of thing, I would never set foot in that place again.
The "G" used also affects how plain old phone calls are handled, but this gets a bit complicated. Turning off wireless data does not necessarily mean that your phone calls aren't being handled with the 3/4G infrastructure. The important part of the "G" specs for this discussion is how how the security of call setup works. The security prior to 3G is broken, which is what allows stringray to work, and is why stringrays try to force everyone's phones to fall back.
There are plenty of caveats, though, so this is more like a rule-of-thumb thing than an ironclad rule.
4G, however, simplifies the entire deal. With 4G, voice calls are really VoIP that get sent over the data network. From a security point of view, the current ideal would be to lock your phone to the 4G protocols, period.
The tradeoff, of course, is that phones fall back to earlier technologies for a reason: the newer techs do not work everywhere under every circumstance, so your phone falls back to ensure that you can still use it when that happens. If you prevent fallback, then it increases chances that you can't make/receive phone calls.
This is the case. I've been lucky enough to have easy access to one of the original IMAX large-format theaters. When I saw a movie in one of the newer IMAX theaters, I found the experience very disappointing.
As a result, I no longer assume that IMAX really means IMAX.