What is the ruling on e-commerce, and what are the evidences for its permissibility or prohibition from the Qur'an and Sunnah?

E-commerce is mostly forbidden due to its common inclusion of usury in most of its transactions, a seller selling what he does not own, a buyer selling what he bought before taking possession of it, and gharar (excessive uncertainty) and jahalah (ignorance). What is permissible from it is that which fulfills the conditions of validity and is free from impediments, but this is very rare.