Front line employees need to be trained in protecting the privacy of your patrons, for two reasons. The first is that many, if not most, privacy compliants I've dealt with are simply customer service issues that are aggravated by the actions or inactions of customer-facing employees. The second reason is that customer interactions are where many smaller privacy issues can rear their heads.
For example, in auditing an insurance broker some time ago, one of the first things I noticed was that computer monitors were plainly visible from the areas where customers were waiting. A nosy parker could look over and see the details of another patron's policies: Something that's surely none of their business.
At the customer service counter, staff have to be very mindful of what they say within earshot of others. I'm reminded of this by an AP story running today on Yahoo News. Though the story is about a lawsuit being brought by the ACLU against libraries' lending policies, the article contains a reminder of how employees need to be trained to be sensitive of privacy issues. When a homeless library patron sought to check out more than three items,
'They said 'Oh, no — you live at a shelter,' right in front of everybody,' he said. 'It made me feel like a second-class citizen.'
Do you think that it will help anyone to potentially humiliate the person in front of others? I don't think so. Perhaps I'm being too forgiving, but I expect the library employee just didn't think about what they said before they said it.
This sort of thing may not give rise to a formal complaint, but employees shouldn't be upsetting the growing minority of customers who care about their privacy and care about it a lot.