One case I have heard of: Loudmouth talked about how he was going to steal a company payroll, to somebody who told the cops among others. So when he showed up where the payroll clerk, and payroll, were supposed to be, so did several hidden cops. But to everybody’s sorrow, the payroll clerk never showed up and everybody just stood around, until Loudmouth gave up and went to drown his sorrows at a bar, and of course, to complain about his bad luck, of course to a cop, who promptly arrest him for attempted robbery. But the judge said no. Loudmouth had done nothing illegal, and thus had attempted nothing illegal.
That poor cop, I’m sure the others gave him crap for it.