Trouble is "all" means "all", not "most." Even one of the so-called religious tolerance sites had enough candor to admit that there were indeed "some" factual cases of tamperings. (Granted, most reported cases, according to their site, proved unfounded.) Adulterated Halloween Candy And it is uncharitable to malign "Christians" for engaging in this behavior, when there is enough blame to go around. Paranoia at large is only natural, following the tylenol tampering case.
Vandalism, however, is a major concern and, if anything, is probably grossly under reported. (Most of my Halloween crimes against property as a pagan youth were never reported.)
Most towns I have lived in, people don't bother to report trashing (TPing, shaving cream, water ballons, egging and the like) around Halloween until and unless it includes feces, arson (excluding open flame that isn't near a car or structure), or actual property damage. There has been an upswing in "Hell Night" actual vandalism - beginning about 1992 in my experience - with rocks through windows and other riotous behavior.