Thats an excellent question. I would say that the best way to defend yourself is to avoid sharing online images with the following:

• Recognisable landmarks or skylines
• Distinctive soil, rock, or vegetation patterns
• Street names, shop signs, URLs, phone numbers, or domain endings
• Vehicle licence-plate numbers, colours, or regional prefixes
• National or local traffic signs, road-marking styles, and curb paint
• Public-service objects such as mailboxes, police-car liveries, and transit stop poles
• Flags, team logos, school crests, tourist merchandise, or event banners
• Architectural styles unique to a small region