"HOWEVER: note that while kits that are opted-out of matching with any kit uploaded for law enforcement purposes cannot be matched to that kit, it is IMPOSSIBLE to completely opt-out of law enforcement use of a kit unless you delete the kit or change it to a “research” kit."
Opting out may make the cops work a little harder but you won't be truly opted out.
Besides, the Snowden Wikileaks have already proven that the NSA hacked Social Security, the Veteran's Administration, most federal institutions, private insurance companies, email servers, employer records, etc. Just because you have a password at FtDNA doesn't mean big brother can't get, or already hasn't gotten access to it.
I'm a huge privacy advocate but when it comes to DNA, I have mine posted online because not posting it doesn't do anything to protect my identity and just slows down my genealogical research.