The following activities are illegal:
- Running a pyramid scheme - This is considered a fraudulent investment scheme and is illegal in many jurisdictions.
- Threatening to harm property - This is considered a form of intimidation or threats, which is illegal.
- Downloading a virus - This can be illegal if it involves malicious intent or violates laws regarding computer security.
- Hacking a computer - Unauthorized access to computer systems is illegal under various laws.
Offering free gifts is generally not illegal, but it could be if it is part of a deceptive marketing practice or intended to mislead consumers.
So, the illegal activities from your list are:
- Running a pyramid scheme
- Threatening to harm property
- Downloading a virus
- Hacking a computer