Very often when registering on a new site I see checkboxes with long explanations saying something along the lines of:
Tick checkbox if you want to receive newsletters.
This is not unusual but a trend is on the rise where companies use the opposite. They say:
Tick this checkbox if you 'do not' wish to receive newsletters. It is usually accompanied by a much longer label, catering to the general theory that users will not read the whole thing and just make a decision based on previous experiences with this type of interaction.
Up until a few months ago, I did the same. I would just assume it says 'Tick this checkbox if you DO want'. Now I have to make sure I read it when signing up for anything.
I personally see this as a very naughty, underhanded tactic of adding people to your mailing list, and it causes me to feel mistrust and disdain for the company employing it.
Why do they do this - is there any other reason apart from trickery?
Doesn't it cause mistrust when users realise or when they receive an email when they clearly thought they said "No, I don't want it"?
Why go against the long established and widely understood interaction?
A weak example of this is mamasandpapas.com sign up:
This is a more honest implementation of this concept, by underlining not they have made it slightly more clear, but I assure you there are other sites who make no effort to distinguish it, where the only way of knowing is by reading all three lines to find the plain, unhighlighted 'not'.
A link provided by Dan Neely has an extensive range of examples of variations on this tactic. http://darkpatterns.org/library/trick_questions