The answer can even be ALWAYS, if remote controlling it is mandated by protocol.
>How often will it be operated remotely, and there's no other police in the immediate vicinity doing traffic control or some such?
That doesn't come into play at all. Do you think those kind of surveillance happens in busy streets with traffic control cops dancing around?
> They are not hard to spot. Watch the media entrances of events, where the on-location vans drive through. Look for where traffic is routed through a single lane. Inevitably they will route traffic past an unmarked van. Or, look for an unmarked van trolling any parking lots within any security cordon.
That "look for where traffic is routed through a single lane" makes me strongly suspect there's going to be traffic officers in the very near vicinity.
In that case those "traffic officers" will be further down directing traffic to the van, not in the van's target.
[Edit: the article also talks about scanning the inside of a house in 15 seconds. That's not going to happen if they drive up the van, park it, get out, walk 1500 feet away, scan the house, walk back... (Yes, I know, they can drive away and back in another vehicle. It's still not likely to be operated remotely in that usage - all the activity makes it too conspicuous.)]