What was the primary illegal activity committed by James Bagarozzo as a parking meter mechanic?

The primary illegal activity committed by James Bagarozzo as a parking meter mechanic involved tampering with parking meter coins. This action indicates a breach of trust and misuse of his position, where he manipulated the equipment responsible for collecting parking fees for personal gain. Tampering suggests that he may have modified the meters to either collect funds unlawfully or divert money that should have been deposited into the city's accounts, showcasing a serious violation of ethical and legal standards in his role.

The other options, while mentioning various forms of illegal activity, do not fit his specific role and circumstance as accurately as tampering with the parking meters does. Collecting money from the meters could be seen in some contexts as part of his job, but without lawful authorization or responsibility, tampering with coins clearly constitutes a criminal offense directly linked to his duties as a mechanic.