As much as we may try to prevent it, our children are exposed to celebrities and their lifestyles. It is up to us to monitor and correct our children's behavior but they can not "un-see" what they have already seen or read. Also, it can affect their careers negatively. Whether we admit it or not, once a celebrity's name is tarnished, we look at them differently, whether it was true or not. We may end up no longer supporting them or works that involve them, etc.
Tabloids seek to inflate their profits by shocking the consumer with lies about celebrities. This practice is unethical and deceitful and should be banned. Both the readers and the celebrities are hurt by these practices. Readers are lead to believe that certain actions by celebrities are true when they are in fact false. This could lead to the readers repeating falsehoods to other people which is problematic. In addition, the celebrities are put down at no fault of themselves. They become the focus of ridicule and potentially harassment.
There are already laws in place that are intended to protect a person's reputation from slander. Any sort of extra censoring of any sort of media would cause people to immediately react badly, especially considering that many believe the government is already infringing on people's rights. Not to mention, everyone already knows that most of the tabloid rumors about celebrities are fake anyway.
I understand it's invading privacy but that would limit freedom of speech. Yes, most of the time these tabloids are lying and that's wrong. These celebrities signed up to be in the public eye. They need to be prepared for what these tabloids could possibly lie about them. The celebrities could also sew for slander.