I've recently written a letter of complaint to my local health club
due to them cancelling a karate class which I attended as part of my
membership fee. In my area, this karate association is quite big with
a number of high profile instructors & clubs dotted around the town.

Now, to cut a long story short they claimed they had given 4 to 5
months notice about cancellation of the class. I've discovered this
was incorrect after speaking to the chief instructor of the karate
association who confirmed no notice had been given and it was
cancelled overnight. When I informed them that I had spoken to him,
they replied with the following statement.

"I would just like to notify you that "Bob Dillion" is a member of
"MadeUP Healthclub" and not an instructor here so he would not be
informed about the cancellation of the class."

Now, to clarify this Bob Dillion was not the instructor at this health
club. One of his collegues was, but in the confusion over the class
cancellation I had called the chief instructor as a primary contact to
find out the suituation. Additionally I had never seen "Bob Dillion",
at the venue so had no reason to believe he had ever attended the
health club.

So, my question is, in revealing members details to the general
public/other members have they broken the data protection act? If I
walked in off the street and asked if Tom Jones was a member surely
this would be the same.

IANAL.  The DPA supposedly covers "personal data"; which
"means data which relate to a living individual who can be identified-"
http://www.opsi.gov.uk/acts/acts1998/80029--a.htm


Unfortunately it isn't enforced.  I'd like to use it against people
sending offers of loans to residents who moved out from my address
years ago.


The definition of "personal data" been interpreted narrowly so that in
your situation I think it is unlikely to apply.
http://www.out-law.com/page-6218