What was the impact on trust?
Instead of thinking there was an error with the site participants viewed the clear text password as a feature.
The presence of the tick box reassured them that the change in convention was by design. It also offered the ability to turn masking on and return to a convention they felt comfortable with.
"The fact that it is there gives me the chance to check what I have typed. It is helping me in my inability to do something simple"
"I think that is much better, as it shows they have thought about it"
"It is protecting me against somebody looking over my shoulder. It gives me a feeling that there is some form of protection in place"