second-hand littering
Refers to where you pick up a discarded object to examine it for possible value to you, then decide that you don't want it, either, and toss it down again.
Second-hand littering has been a hotly-debated topic for eons. One the one hand, a person who picks up something that someone else has already thrown away likely feels that it's not his responsibility to go and find a trash can for said discarded object just because he briefly handled it, since he was not the one who originally discarded the item, and he himself is a conscientious bloke who never litters like that with his own trash. But many other humans disagree --- they feel that by tossing away the item again, this "second" person is littering just as much as the "original" litterbug, since he, too, is dropping an unwanted item on the ground. "Dropping any unwanted item on the ground instead of in a trash can is still littering," they insist, "regardless of whether the item was already there or not!"