Spinning bolt hangers...should I be worried?

Was out climbing a few routes at The Watermark in Boulder Canyon this morning and noticed that several of the bolt hangers were pretty loose, a couple were even spinners. Is that something I should be worried about? And is there any easy way to tighten them down?

A warning about "spinners" on compression bolts?

How accurate is this? Am I gonna die?

"By far the most common iffy bolts are the 1/4-inch Rawl button-head and its threaded-end sister. These probably represent 95% of the 1/4-inch bolts in place. In good rock these can be surprisingly strong, but only if the hole has been perfectly drilled - a very rare scenario for hand-drilled placements and impossible to verify. They should be replaced in anything but the best rock - especially if they are spinners or in an orientation (such as a rappel anchor) where an outward pull may result."
- copied and pasted from safeclimbing.org

I've climbed past a million of these things, clipped every one, and never took the ride (Thank God!)

Any opinions?

I believe OP is saying the hangers are spinning, not the bolts.

jsittler - if it is only the hanger that's loose, you can tighten them down with a small wrench. There are even a couple nut tools that have a hex wrench stamped out right in the handle. Just snug it up gently, DON'T tighten with all your strength. That's how bolts break.

Here is a resource with a lot of good information:

mountainproject.com/v/fixed…

Should be fine