At the time of the ad, the more information about them users are known the more convenient it is for companies. In particular, telephone numbers are a personalized and valuable tool marketing for each company. But how can you avoid this?
Do not call at first phones belonging to political campaigns, polls and surveys, charities, non-profit organizations and companies that you may have worked with in the last 18 months or have tried to work with in the last three months.
Both political campaigns and charities often share or sell donor information to other campaigns, charities, and nonprofits.
If you call a toll free number, it could theoretically automatically add your number to databases without asking you through Automatic Number Identification, even if you have enabled Identification Blocking.
Privacy policies for all the sites you interact with are well hidden in the "fine print" that only a lawyer can decrypt, so if you give your number to anyone site, is almost certain to be found in some database.
Another way to get your phone number in the wrong hands is through data breaches, which are very common.
Via the site Have I Been Pwned, you can use your email address to see the companies that have been compromised to find out if you have an account with any of them. Generally avoid using your phone when creating a new account.
If you own any kind of real estate, you have probably sent a message or been asked to pay in cash to buy your property.
Real estate transactions create public records and in combination with other resources can make it possible to determine the owner's phone number.
The best thing you can do is have a second backup number, which you will use in all your unnecessary, short-term communications.
The application Google Voice is a free and easy option to add a second phone number to smartphone which you can use to keep your real phone number private. Filtering her spam Google and call control are also great tools and when the number starts receiving a lot of unwanted calls or messages, just delete the number and start using another one.