Is it permissible to buy shares in Facebook, given our knowledge that the site contains indecent pages, pages against Muslims and the religion of Islam, and illicit communication between the sexes?

For the purchase of shares in any company to be permissible, it is stipulated that the company's activity itself must be permissible, that the impermissible does not largely dominate it, that it avoids Sharia (definition) violations such as gharar (definition) (excessive uncertainty) and maysir (definition) (gambling), and that it does not invest its money in usurious banks. If these conditions are met regarding the company's shares, then their purchase is permissible; otherwise, it is not.