[Kiro]

I treat everything I do on Facebook as public and permanent information. With that mindset the experience is rather pleasant.

[bigbugbag]

Not public, privately own by facebook (and partners and clients) and aggregated with everything that is actually public and every other privately own data they could gather.

Then used to target you in every possible ways.

[owlninja]

I get most of the personal data concerns, but what exactly is the issue with targeted ads?

[antocv]

Changing your behaviour.

Ads are a hostile action.