What is the difference in meaning and use of the phrases "illegal activity" and "criminal activity"? Is one broader than the other?
Illegal activity is activity that contravenes the law.
Criminal activity is illegal activity that is also a crime. What constitutes a crime is usually detailed in a criminal code in each jurisdiction but can derive from common law crimes like murder, arson, rape etc. A crime is an offense against society and is generally prosecuted by the state.
For example (may vary by jurisdiction):
- Breaking a contract - illegal
- Stopping in a No Stopping zone - illegal
- Negligently polluting the environment - illegal
- Breaking someone's arm - crime
- Deliberately ramming someone with your car - crime
- Recklessly polluting the environment - crime