Care to share any strange occurrences of "the internet is watching us"?

This can be fun or it can be downright unsettling, but sometimes coincidences on the ‘net can make you think, “Are we being watched”? Or tracked perhaps.

Here’s a related comment by @Aster from a recent thread:
”We’re being watched and spammed everyone. When I look at an Ebay picture it appears on my Facebook page!! Just from looking!!”

This, or something similar has happened to me numerous times. Here’s today’s example:

I’m on LinkedIn and as I scroll through the “People You May Know” section, I see my mother-in-law’s tenant. I open his page and see that we have no connections in common, no shared organizations, places of business, schools, skills… nothing. We’re not even separated by mutual acquaintances, and yet LinkedIn thought I might know him. Which I do, but only in real life. How did they know?

Tell me of your moments of “being watched” on the internet.