The end justifies the means. Are you agree?

If not, then where is the boundary where we have to stop? I mean "Free/Libre/Ethic Software" movement.

Only for example, we may trick people about non-free software:
"Sensation! Skype can eat your brain!!!"

And this may be succesful:
"This is awful! I don't want Skype ate my brain, so I will switch to Ekiga".

Some years later:
"Now I know the truth. Skype can't eat my brain. But now I also know, that FLOSS is the best! Thank you for tricking me! Your lie gave me freedom!"