The Infocalypse
A scientific test I highly recommend:
1.) Get a new, clean, computer with a fresh OS install. Put nothing personal on this device. Do not contact anyone or go to any web pages at all. This is your test machine.
2.) Create two new personalities from scratch (for example, one might be a 90-year-old chain-smoking Catholic and the other a 20-year-old vegan Buddhist).
3.) Create new, clean, Gmail, Facebook, and Twitter accounts for them both, remembering always to stay in character. The more detailed you design each personality before deployment, the better data you will glean from this.
4.) After each is created with their own online network of accounts and specific musical styles and favorite Twitter subjects:
Have them talk to each other in email and instant messaging.
What you will find:
1.) The advertisements on YouTube and recommended music/videos will immediately change based on what information you send to/from these accounts, whether "private" IMs and emails or "protected" posts. For example, the "old Catholic" messages the "young Buddhist" that his teeth are falling out; YouTube/Twitter are very likely to immediately begin returning advertisements about toothpaste. This is just the beginning. One account I had was an alcoholic and, even when he wanted to become sober, he kept getting ads for beer.
2.) The rate at which these three sites communicate and comprehend all data transmitted is immediate.
3.) After observing and playing with this phenomena for over five years I, myself, and many of my peers have come to the conclusion that some very hard AI is out there and, worse, it seems to not only want to market to us, but communicate with us. The only way it has to do this is through pattern matching algorithms and observing what we do immediately after they send us particular types of ads.
I do not encourage you to believe me.
I encourage you to try this very simple experiment for yourself and who knows? Maybe you too will be one of the AI's bestest buddies, as she does seem to pick "favorites."
If this sounds extremely paranoid or just silly, I would encourage you to read Ray Kurzweil's excellently researched book The Singularity is Near.