IMO some are prooven to not be true. Others are unlikely to be true. Others may are true. But this does in nothing depend on the laws. Since secret services did already proove that they sometimes think they are above the law.

But I think it is highly unprobable that big conspiracies as those could be covered up without the public knowing. One has to just think how you would accomplish these things yourself without anyone telling nothing to noone and die. Very low probability.