Nor would they be allowed to create their own temporarily-installed pole with a camera on the top.
So to me, the public view argument only holds if the public was capable of it.
In short, you have no expectation of privacy when it's possible to be seen from a public right of way. I really see no problem with what LE did here.
Utility poles are generally owned by a private company though or the local government and are regulated.
Members of the public are not generally permitted to hang things or attach things to them, and since they are usually located on private property or property that the local government has rights to, the general public also isn't generally permitted to place things on them.
The idea that the position is privileged because it's a utility pole and it's illegal for civilians to modify them is a pretty weak argument. I'm no even sure that's true; people post bills and such on utility poles all the time. I'm tempted to nail a gopro up and see what happens.
If they had just taken a metal pole or a low-altitude drone perching on a tree as a camera base, you'd be fine with it?
I mean, a convicted felon was walking around with a firearm in broad daylight outside, within eyeshot of the road. The idea that this can't be observed from external perspectives by law enforcement but a civilian could legally do it is pretty weird. Weirder than the idea that law enforcement could use surveillance drones, to me.
I agree with the outcome of the case, just not necessarily how they arrived there.
As for attaching things to utility poles, etc. yes, most cities and local governments have rules/laws about that, they're just usually not strongly enforced. As an example:
"No one is allowed to attach to utility poles in the state of Pennsylvania without permission from the pole owner."
https://www.pplelectric.com/at-your-service/for-contractors-...
As long as the government had a warrant, or this was a private citizen exercising their legal rights, I have no problem with it.
What I would have a problem with is the government performing surveillance that only they could legally do without a warrant or evaluation by a judge of some kind.