The City of Salem has hundreds of local ordinances that you could easily have broken without even knowing it. For example, according to Revised Code 76.030, it's illegal to "wash fruit upon any sidewalk, landscape strip, street, alley or public park" in certain downtown areas. In other words, if you ignore the five second rule ("if you dropped it on the ground less than five seconds ago you can still eat it") and let your apple roll for ten, don't compound your crime by washing it.  
A 61-page index of revised city codes (that's a 61 page index, not 61 pages of codes) can be found at cityofsalem.net under "Revised Codes."  The activities addressed in just the first 20 pages include such noteworthy concerns as dropping articles from aircraft, unlawful archery, toboggans and icebox abandonment.

Other actions that can be used against you in a court of law include using a slingshot or bean shooter (95.050), picking flowers in a park (94.030), owning a pot-bellied pig (see "Miniature Swine, 119.070"), or launching "missiles" downtown (no, this isn't a knee jerk reaction to 9/11,  94.070 addresses items that are "thrown, batted, etc.").