True. The power of tracking through big data analysis can be really really dangerous. Having a burner cellphone (B) one never used to call anyone (C) is useless if it's always carried around with the main one (A) so that it always updates through the same Wifi connections and links to the same cell towers at the same time. A and C's are already related, so a quick analysis will relate also A and B, then B with C's although B and C's never called each other and don't share their respective numbers in their phonebooks.