So my birthday is coming up, and I figured I would order some goodies for a good time. I placed my order, sent my encrypted address, etc. etc. Fast forward about a week and I check my mail box where sure enough, my pack is there! Everything is great and looks like it'll be an awesome birthday for me. I take the pack in, open up and out fall a little note that says "Happy Birthday! I hope you have a wonderful day!" Along with my substance. Needless to say, I nearly shat myself wondering where my OPSEC flaw was and how this vendor knew it was my birthday. I spent a good half an hour freaking out before realizing that it was just part of the vendor's stealth. Duh.
Plot twist, your mom is the vendor.