Here's where US Federal law gets a bit ambiguous about "Outdoor Laser Use"
LaserPointerSafety.com -U.S.: Illegal to aim laser pointers at aircraft or their flight path
So it is subject to interpretation within the law above for civil penalties for shining a laser into an "aircraft's flight path" with enforcement by the FAA through local police/sheriff/constables.
LaserPointerSafety.com - US: Latest 2012 laser/aircraft incident statistics
Note that any laser beam visible by a pilot during flight can and will be reported as a “laser incident”, regardless of whether it is an actual hazard or not, nor whether it is logical or reasonable for the FAA to track it as a valid aircraft “laser incident.
So in consideration of the above, the apparent risk of any outdoor skyward laser use (while being well outside the FAA defined laser free space around an airport) would be:
) To inadvertently illuminate an "unseen" aircraft or its flight path
(Obviously aircraft at high altitude at night may not be readily distinguishable from the back ground of stars, where enough time should be spent scanning the sky to make certain the area the laser will be directed is free and clear of any aircraft's signature tell-tale point of light movements)
) If the laser beam is observed and reported by an aircraft pilot as a FAA-reportable laser incident
So how much effort will the FAA exert to enforce either of the above is probably not very great. The one thing I am concerned about is how many of us in using our laser pointers outdoors have contributed to the FAA's “laser incident” running total of events.
Otherwise, it should be noted that the general public seems to often call the police when any outside laser use is witnessed. Case in point, I have seen several local accounts reported in the police log section of the news where individuals made such reports and officers were dispatched to investigate, although I am unaware of any local laws against such use. Law enforcement have also been known to arrest first only to let the court system work it out.
I don't know if any of this helps or not as this is just my take on the subject, where I am not a lawyer and my 2 cents may be overvalued. :wave:
I just needed to know, for, when I get a new laser, the first thing I do is see how visible at night. 
I think I'll be doing that now to avoid conflicts.
