My right to privacy

With the growing phenomena of social media, one of the concerns that are constantly being addressed is that of privacy and peoples perceived right to keep things private that are put out onto the public domain.  Between social media sites such as facebook and twitter peoples entire lives are being documented and put up for others to view.  In the past privacy has always been a right that could be always be expected, what happens between friends over the weekend never had to face public scrutiny, but with the growing popularity of documenting ones own life how much privacy will remain in the future.  When applying for a job is it ethical for employers to look into facebook and see those embarissing photos of you, or follow twitter to see what you are doing throughout the day.  Privacy was a lot easier to enforce when private things were kept in private but now that everyones private life spills into the public domain the lines become a lot more blurry.