You use anonymous SIM cards

The topic of mobile phone monitoring is complex and cannot be fully covered in this context. However, it is important to understand that security apps cannot do anything about such monitoring, for example because it affects data that is already stored with your provider and not on your phone. Or because the apps themselves do not have access to your phone's proprietary radio chip and therefore cannot see silent text messages, for example. Or because the attack takes place in the wireless network between network providers. Or because your mobile provider simply sells your data on. So relying on apps or changes in behavior won't help. The only defense is anonymous SIM cards. Also bear in mind that over 100 government agencies in Germany can access people's phone numbers and vice versa without a court order.

You can order anonymous sim cards on the Internet. The search engine of your choice will help you. This project deliberately does not want to advertise individual services. Sometimes there is also scam. Please keep in mind that anonymous cards are probably often registered by marginalized groups like migrants to make some money. Many cards are backed by real people who vouch for you with their own name. Therefore, only use the card to protect yourself.