What is the truth about the aforementioned website, and is it considered a fitna?

The website is not concerned with judging individuals. It advises the questioner with a general recommendation: "Truth is not known by men; know the truth, and you will know its people." It also advises studying the Sharia (Islamic law) based on evidence, asking scholars, consistently performing the night vigil (Qiyam al-Layl), and supplicating with the supplication authentically reported from the Prophet (peace and blessings be upon him) for beginning the night vigil.