On on my pet peeves is when the lead flight attendant announces during the boarding process "this flight will be completely full, every seat will be taken." And there are a bunch of empty seats when boarding is completed. Is there a reason that they lie to the passengers? This does not have to be. Tell us it will be almost full if you want. It is somewhat like crying "wolf". When you have been lied to a number of times, you don't believe it - but still question the integrity of the FAs. If company SOP for FAs to do this, does company realize that FA is being told to deliberately lie? Most recent occurrence - Flt 409, PHX-BWI Feb 17th.