No mention of whether the data was encrypted or plain text. That such data is shipped by an apparently insecure method shows that BoS may not yet be taking ID theft and customer security seriously.
**UPDATE** This article reports that the data was unencrypted:
http://www.computerworlduk.com/management/security/data-control/news/index.cfm?newsid=3341
And this article reports the information was sent by standard, unsecured Royal Mail:
http://www.theherald.co.uk/news/news/display.var.1443290.0.0.php
BoS claimed it was "almost impossible" that any financial fraud could be committed with the limited information held on the disc, HOWEVER they omit to say that the information on the disc could be used in identity theft from its customers without impact to BoS.