How do we know that LHC will not be detecting a "bad particle" we are quite unaware off?

I am reading all of the posts here, but to me, it still appears that many users are ignoring the fact that none of these experiments have been observed as of yet. Its mostly simulation that physicists are justifying their safety concerns from. I don't think this is a safe way to confirm that everything is good to go.

I've read the safety concerns page on the CERN website, but the information provide to me, is not adequate enough.

Also, for the regular people, that mostly comprise this society, how come they are not being clearly informed about this "6-billion dollar" experiment. The media is not even stepping up to the plate. Something is plain wrong here, a missing link I should rather say. If anyone can clear these thoughts up, that would be appreciated.

Thanks.