Public nudity laws. Who does public nudity hurt? What if a guy wants to masturbate in his own car? What if he wants to flash people? Who does he hurt? No one. Oh, unless you count his offense to their moral sense.
You got me on that one, except that public masturbation is indecency, which takes away a parent's ability to use public facilities with any expectation of comfort. There is really no substantial societal difference between public masturbation and fondling of other people without their consent. I believe what is being legislated with those particular rules is the affront to others with socially unwelcome behavior. This law is also particularly used and enforced where no general expectation of such behavior exists. For example, a public nudity statute would be unenforceable in a strip bar, as a general expectation of such behavior exists there, so it is unlikely that a person's sensibilities will be affronted. This doesn't exist for example, at McDonalds. There is a reasonable expectation that a visit to McDonald's will not result in the viewing of public fisting of a walrus. That's reasonable. If you had a sign in front of a business that said "Come in and witness the public fisting of a walrus" then such behavior would not run afoul of most statutes other than the animal cruelty. (Animal cruelty laws ARE inherently altruistic). So actually maybe you don't have me there. Most public decency laws actually are a reflection of expectation and are similar in wording to assault laws (not battery). Remember that assault is unwelcome speech or behavior which is delivered in a beligerent or impertinent manner, and is generally intended to hurt, cause discomfort, or offend another person. It is intended to cause HARM. Notice the similarities with decency law?