Yesterday after walking home from the tube, the woman walking in front of me dropped from her bag something that looked like a few cigarrettes. Another guy also noticed it too, but kept quiet. I was about to bring her attention to it and then, as I got closer, I realized these were tampons. So I just shut my mouth and kept walking. I'm sure she would've prefered losing a few tampons than being told in front of several strangers that she just dropped a few tampons.
I exercised quick thinking and sensitivity in a manner worthy of praise. Yay me.