There is evidence that the USPS has been logging all that metadata.<p><a href="http:&#x2F;&#x2F;www.nytimes.com&#x2F;2013&#x2F;07&#x2F;04&#x2F;us&#x2F;monitoring-of-snail-mail.html" rel="nofollow">http:&#x2F;&#x2F;www.nytimes.com&#x2F;2013&#x2F;07&#x2F;04&#x2F;us&#x2F;monitoring-of-snail-mai...</a><p><a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Mail_Isolation_Control_and_Tracking" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Mail_Isolation_Control_and_Tra...</a><p>I&#x27;m not saying that it&#x27;s right but it apparently is happening.