We don't know what system they are using to collect the data, to hold the data, and to anonymize the data, whether it's just by attaching a code number, but if they're going to use it in the way that has been described, it would seem that as long as they have that data, it is accessible to a potential breach. A breach of this sort, of deeply personal financial information, could have political overtones in terms of the way it might be used if that information was not successfully held.
On November 1st, 2018. See this statement in context.