His actions are neither illegal nor entirely ethical, falling somewhere in a gray area.

Source: Tatoeba

In all of the gardens in my city it is illegal to trample the flower beds.

Source: Tatoeba

Was what Ziri was doing illegal?

Source: Tatoeba

It's illegal to park your car here.

Source: Tatoeba

It's against the law to carry weapons.

Source: Tatoeba

You know this is illegal, don't you?

Source: Tatoeba