TELUS Mobility reserves the right to limit usage and will charge $10 per additional MB for excessive usage over 50MB of data per month.
If they advertise as "Unlimited", by no definition of the word does it matter if they put a superscript notation with the fine print reading the above statement and it still be considered legal (atleast in the states). If I were some of you, and this goes for Rogers customers as well, I'd look into a class-action lawsuit against the two providers. False advertising and purposeful misrepresentation are very illegal business acts in the United States, so I'm guessing the laws are very similar in Canada.
Atleast one of you customers would have to be a lawyer or know a lawyer who wouldn't mind putting some time into a fairly simple case of purposeful misrepresentation of pricing structures.