这些照片，千万别发在朋友圈！

Group 1 - The article emphasizes the importance of not sharing personal information on social media during the summer, highlighting various types of sensitive information that should be kept private [1][2][3] - Specific items to avoid sharing include train tickets, flight tickets, boarding passes, license plates, identity cards, passports, bank card details, location information, unverified information, and personal details of others [1][2][3] - The article suggests practical steps to protect privacy, such as adjusting social media settings to limit visibility to strangers and being cautious about sharing information in public forums [3]