Is passive wireless discovery through war driving in itself is an illegal activity?

Passive wireless discovery through war driving is not inherently illegal, as it typically involves merely scanning for and mapping open Wi-Fi networks without actively attempting to penetrate them. However, the legality can depend on local laws and regulations regarding privacy and unauthorized access to networks. If the information gathered is used for malicious purposes or if the act violates terms of service, it could cross into illegal territory. Always consult local laws to understand the specific legal implications.