I'll give you this. Unlike most truthers, you at least have the guts to admit you're calling firemen and the rest of the professionals who don't support these retarded theories cowards.
You can know the truth and remain silent. This doesn't mean you are necessarily a coward, it means you care for your family and want to continue with your means of supporting them. When some that do come forward with the truth are ostracized, the rest get the message loud and clear. Psy-Ops 101.
The firemen and first responders weren't silent. 160+ of them gave interviews that were suppressed for 5 years. When you tell what you know, and it does no good, you've done your best. If you want to know what they think, just go read what they said.

