How Can I Protect My Privacy?

[DunbarPappy®ϟϟ]

Yahoo could have an entire section just for this, so briefly:
Never, and I mean never, post something in ANY social Network site you wouldn't want blabbed on National news.
Protect Your Online Privacy (Without Reading All the Fine Print); https://www.pcworld.com/businesscenter/a...k=rel_news

See this site: https://www.eff.org/action for some measures you can do. (Maybe even join?)

More sites:
Erase Yourself From the Web; https://www.pcworld.com/article/223682/e...e_web.html

https://www.pcworld.com/businesscenter/a...rates.html
June, 2012

Add-on for Firefox that compiles several functions in order to disambiguate you from many social 'services', like:
Digg, Facebook, Google +, Twitter, Yahoo.
Homepage: http://disconnect.me/
Also provides notices about what's being blocked

As you can see, this is a Herculean task, and it only gets worse.
The proliferation of 3rd party tracking devices (principally 'tracking cookies') that browsers fetch automatically brings along unwanted and unknown consequences.
A study (UofTexas: http://arxiv.org/PS_cache/cs/pdf/0610/0610105v2.pdf ) was able to isolate "micro-data" inclusions (representing the statistical rarity of the identifier for any given user) and by correlating that with other statistical data, determine who these people are exactly.
These databases are cumulative (and widely dispersed), and because of their unregulated nature, can and are leveraged for other purposes than the innocuous gruel we are served up by the Advertising ghouls (such as "it's for your own good", or "We take your privacy seriously".)
Once information about yourself is released (voluntarily, or by subterfuge) there can be no assurance that it will be safeguarded, or that will remain strictly in the realm of "harmless" ad delivery.

Good luck.