<p>Basically, a good way to never trust "it's okay, the data is anonymized" again is simply knowing what the "Hemisphere Program" is.</p><p><a href="https://www.eff.org/cases/hemisphere" target="_blank" rel="nofollow noopener noreferrer" translate="no"><span class="invisible">https://www.</span><span class="">eff.org/cases/hemisphere</span><span class="invisible"></span></a></p><p>In short, the US government got access to number from, number to, datetime, length and sometimes location information for every call passing through AT&T's network from 1987 to today.</p><p>Then they ran an algorithm to de-anonymize every burner phone based on behavior. They did this because maybe some of those burners were used by drug dealers.</p>
