Does looking at websites that deal negatively with famous people under the pretext of showing the truth count as attending a backbiting gathering, and what is one's duty towards them?

As for well-known sinners: if they do not publicize their sins, then they should be concealed, and it is not permissible to delve into them. If they do publicize them, then many scholars have held that there is no backbiting in their regard. Others have stipulated an overriding benefit, and this is the preferred view; for there is no benefit in pursuing their news, due to the propagation of indecency, the violation of honor, and the incitement of the public that it entails. The default is the prohibition of delving into people's honor unless there is an overriding benefit. As for websites that aim to reveal the truth in a religiously permissible manner and with an overriding benefit, there is no harm in viewing them.