There is no harm in (someone) doing (something)

1. Doing something may be good, pragmatic, or beneficial, and will not cause any problems or harm.

2. People say there's no harm in doing something to mean that it will not cause problems and may have a good result. 

E.g: They are not always willing to take on untrained workers, but there's no harm in asking. As I see it, there is no harm in cooperating with the police.