ANd how could I tell? Because today I found this page on Facebook. There is something about an election year, particularly for municipal elections, that brings out such groups.
I find taxpayer advocacy groups both fascinating and annoying. In Canada the grand-daddy of all such groups is the Canadian Taxpayers Federation. One of their early leaders was a young Stephen Harper (for the record now PM Harper is no longer in the CTF good books because he has not been the strict fiscal conservative they wanted). The CTF is a right-wing, fiscally conservative, small government group that is loud but not nearly as effective as they think. And I am also not at all sure they are as well-supported by the general public as they would like to think. They like to make a big splash by calling for idiotic things like making party leaders sign "no new/raised taxes" pledges during an election campaign--sort of like Grover Nordquist in the US. The difference is that Canadian politicians, at least the ones who end up in power, even if they are suckered into the idiotic photo op, are often able to ignore the pledge and act in a more responsible fashion.
At a local level (and in more than one municipality) I have found that the Taxpayer defence/advocacy groups end up looking more like whiners than anything else. They tend to attract the people who want a forum to complain either that taxes are too high or services are not being appropriately provided or in fact both at once. [It always amuses me when people complain about a lack of a particular government service while simultaneously complaining about tax rates being to high/being raised too often. It seems that those two complaints are counter-productive to each other.]
The most disturbing part of the group I found today is that they are insisting that they remain anonymous. That is their right of course. And it is entirely possible they have valid concerns about issues around town (although I have yet to see one I find valid posted to their page). But the optics are not good. To be taken seriously about opening a space for debate would mean being open about who you are. And to really be taken seriously about these issues in a municipal election year would of course mean putting your name on the ballot in the fall. But of course then you might win and learn that you can't actually do what you call for because it simply is not realistic. I have seen that happen to at least one member of a ratepayers group before.