After the post below, I was informed through two independent sources that their families and relatives have direct access to facebook without using proxies. Through a third party, I was also informed that at least one person in Iran was unable to access facebook.
It appears that BBC's account was either inaccurate or according to CNN the ban was temporarily lifted a few hours after it went into effect only to be reinstated.
ILNA, the Iranian Labour News Agency based in Tehran first reported it yesterday and has been the primary source of this developing story.
I welcome any of you to provide us with more information regarding this issue, especially from people trying to access facebook from Iran.