Although I hate to interrupt this regularly-scheduled outrage, but has the OP considered the difference in the reasonableness of precaution?
For example, if someone comes to the authorities (whether CIA, TSA, local police, etc) with information that BA flights are about to be bombed. Now, one can either let the flights go forward while one investigates the accuracy of the sources, or one can cancel the flights. Obviously, the latter was chosen. That the information later proved to be false does not mean that the decision-making process was flawed; because the process was based on uncertain information. To expect authorities to instantly be able to judge the credibility of every source of information is fantasy.
On the other hand, if someone produces information that Iraq has WMD, but there does not seem to be a plan for an imminent attack, then obviously caution would dictate that more time be taken to assess the information before an invasion of Iraq is launched.
So, I ask each of those who have posted to this thread so far: if compelling, but unverified, information comes forward that there is a terrorist attack planned on one particular airline, when do you think the airline should be informed of this information? Should the government encourage the airline to continue operations while the veracity of the source is investigated?