Sync.ME's database is made up of publicly available phone directories and Sync.ME user crowd sourcing !
Sync. ME database is constantly growing and getting smarter every day. A number you search for today that provides no results, could be reported into the database tomorrow. Our database reacts in real-time to our users’ reporting and tagging, allowing us to expand the database on a daily basis. As well, numbers change owners frequently, and our users often help create a smarter database by suggesting name changes, which are verified within 72 hours, before they are officially changed.
You can delete your info here https://sync.me/optout/