I have seen people genuinely out for a walk at 2am, including walking their dogs, so not everyone wandering around is up to no good. Heck, when I was much younger, I used to go for a 5k run at midnight to blow off excess energy. Oh, to have that kind of energy now ...
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Anyway, on to my (slightly) scary story ...
I set my scope up at the front of my house, because I'm "treed in" on the other three sides. In fact, I set up right on the kerbside due to the slope of my front yard and driveway. Consequently, I get a lot of passers by, both in cars and on foot, who usually greet me with, "Is that a telescope?".
Back in February (IIRC) after a long break, I had a particularly late one - I was still out viewing at 3am - and for the last couple of hours there'd been not a sound. It was the quietest night I can remember for a long time.
As I gazed through my scope I heard a strange sound in the distance:
Scrape, scrape, scrape .... kthunk, kthunk.
It was faint and intermittent.
I viewed some more, and the sound grew a little louder:
Scrape, scrape, scrape .... kthunk, kthunk.
Over the next few minutes the sound stopped and started, each time a bit louder and getting nearer, as I could hear it shift from being behind me and going towards my right:
Scrape, scrape, scrape .... kthunk, kthunk.
At this point, just in case, I retrieved my "persuading stick" from inside the house and lay it against the mount tripod:
Scrape, scrape, scrape .... kthunk, kthunk.
I can't see the road to the side, only the small side street directly in front of my house, due to the aforementioned trees and fence, so I still don't know what
the hell is making this noise and don't want to tempt fate by going out to the "main" road to see, in case I draw too much attention to myself and my expensive equipment:
SCRAPE, SCRAPE, SCRAPE .... KTHUNK, KTHUNK. 
Finally,
the thing came into view past the edge of the trees at the corner:
...
...
...
It was some guy, drunk as ten men, staggering along, dragging a steel esky along the pavement behind him. The esky looked like it was originally on a trolley, but no longer had wheels, and the "kthunk, kthunk" was the sound when the remnants of the wheel mounts on the bottom hit the gaps in the concrete pavement. Occasionally, as he was obviously barely able to stand, he would pause, sit on the esky, then summon up the strength to continue for a few more metres. He paused and sat at the street corner for a minute or two, then went on. (And this is when I recalled that there had been party noises up at the top of the "main" street earlier in the evening). He didn't even notice I was there.