PSA because some people don't seem to know that. Those weird barcodes found on letters contain your zip/postal code (which in some places can point to really specific location). You may want to blur them out when posting photos of letters online.
@gorol Better yet, sharpie over it and otherwise use solid color blocks, blurs can be undone at this point.
But yes, absolutely an easily overlooked part of opsec! Don't forget that cameras are good enough a discarded letter envelope in the background could very easily be read too..
@IrisKalmia I was thinking about adding this advice, but decided not to for clarity. Solid black block are the only way to censor something reliably, but they have to be applied correctly. Countles PDFs, PPTX presentations and vector images were censored with black boxes that can be removed. And that's not all; contract between EU and AstraZeneca although censored correctly had first 255 characters off all paragraphs in table of contents. OPSEC is hard.
@IrisKalmia Also sharpies are not ideal, sometimes little image manipulation can reveal what was underneath. GOOD OPSEC IS HARD
