@shmibs @Moon every single member of the church has all of their information on record. this is for, as for their claims, two main reasons:
1) making sure everybody is accounted for in terms of church callings, tithes, and for the administration positions to get in contact with members to establish those things and set up meetings
2) establishing a better sense of community within your local church, where anyone can reach anybody else. they used to have church registries for all the members at a local church, we had one hanging up on our wall for years with everyone's name/number/address in it. if someone needed something, they'd have everyone's numbers and could call people up to get some help.