I'm on Prepay Plus (the 49c min/20c text/50c MB data rates) - i.e. when 2degrees prepay customers don't have a Prepay Plan.

I received a text from 2degrees today, stating that data sharing has stopped because I do not have an active Prepay plan. [I receive shared data]

I checked my 2degrees, and I found that my data was getting charged to casual data from yesterday evening onwards - fortunately a very small amount of data was used.
Some ahead of time notice would have been appreciated...

The documentation on shared data has also been updated (previous version here) to mention the Plan requirement - e.g:

> Numbers you’ve shared with will only be able to use the Shared Data if they have an active Prepay or Pay Monthly Mobile plan.