Data protection ?

What are the actual specifics of the data protection act?

How confidential are people's names and addresses ?

Today i, along with around twenty other job seekers went to an induction morning with learndirect / jobcentre/ a private care company.  To learn about a career as a support worker in the care industry, working with vulnerable adults with autism, mental and physical disabilities.   

Part of the presentation included a computer map of our city with addresses of their clients marked on the map.  I asked if these were care homes and they replied no.  They worked with individuals in their private homes.  So these were actual home addresses of vulnerable people with house numbers and street names.

Were they breaking the data protection act ?????