If we learned one thing from the housing crisis,  it's that less-affluent people bore the brunt of subprime loans and the foreclosure wave that followed, which some banks still haven't made right.

Nonetheless, a new analysis shows that people in wealthy neighborhoods complain a lot more about all aspects of the mortgage process, from brokers to servicers to underwriters.

The Consumer Financial Protection Bureau has been taking and tabulating complaints about all different kinds of financial services for a couple years now. They don't collect demographic information, but the consulting firm Deloitte was able to break down mortgage-related complaints by Zip code, and found that the areas with the highest median incomes were the loudest:

The wealthy whine more. (Deloitte)
The wealthy whine more. (Deloitte)

The pattern is similar with age -- areas with older people were also the source of the most complaints. It's possible that older people may also have the most trouble with their loans, though, so that's not quite as surprising.

One could imagine any number of reasons for the disparity (the Bureau itself declined to speculate). Rich people tend to be more Web-savvy and have more time on their hands, but the CFPB also takes complaints via phone and fax, so it's broadly accessible. The more likely explanation is that word of the complaints database -- and those of other regulators that feed into the CFPB's -- has simply penetrated further in wealthy communities. (And yes, it could just be that rich people feel more entitled to the help.)

The banking industry has consistently carped about the complaints database, especially after the U.S. Public Interest Research Group used it to call out the most vexing banks. Camden Fine, president of the Independent Community Bankers of America, thinks it's mostly a bunch of bellyaching anyway.

"I would be shocked if the CFPB said that some significant percentage of the complaints they get are horrendous, horrible wrongdoing," Fine said. "Any time you set up an 'olly olly oxen free' system, you're going to get every nutcase in the world calling those complaint lines. Almost all of them are going to be something that could be resolved by banks, or the nutcases. If we had an open line, we'd be flooded by every nutcase in the world. Everybody has a story, and everybody wants some attention."

Which is, of course, the same challenge faced by crowdsourced sites like Amazon.com and Yelp, which have to deal with poor quality, nutty, and downright fake reviews all the time. The CFPB at least verifies that each complainer is actually a customer of the institution they're grousing about (not just random nutcases, as Fine worries). And so far, it looks like financial institutions are trying to give their customers fewer reasons to complain -- or even be confused and in need of help, which the Deloitte report found was a greater source of complaints than actual grievances.