There's more than honesty at stake here... I'm pretty sure you could run into problems with the FTC (in the USA) if you disregard this principle. See for exampl

There's more than honesty at stake here... I'm pretty sure you could run into problems with the FTC (in the USA) if you disregard this principle. See for example http://bvyer.net/info/conduct http://bvyer.net/info/conduct. Other countries might have similar rules.