How can one trust fatwas and financial transactions online, especially concerning banks that bear the name "Islamic," and is dealing with them permissible under Islamic law?

Islamic banks were established as an alternative to interest-based banks, and the assertion that it is absolutely forbidden to deal with them is incorrect. Among Islamic banks, some adhere to Sharia regulations, while others are negligent. Therefore, it is necessary to review the Sharia board of each bank. If they permit a certain transaction, then their ruling may be adopted. As for trust in the fatwa, the questioner should ask scholars known for their knowledge and piety.