The latest survey, which we report this week, shows volunteering has actually declined a bit during the Year of the Volunteer - about eight million people said they'd volunteered in the past three months.
That doesn't necessarily mean the year has been a failure - a lot of promising initiatives have got under way that won't necessarily bring short-term results but which are likely to bear fruit in the future. It's only part of the picture, and it's only one survey.
But when you compare the results with the Government's figures, the matter takes on a different dimension. In his introduction to the recent document A Generous Society, Home Secretary Charles Clarke says "more than 20 million people volunteer every month, 1.5 million more than in 2001".
The big difference is explained by the fact that Clarke's figures, based on the Home Office citizenship surveys, appear to include both formal and informal volunteering. The latter is defined as activities such as helping a neighbour to fill out a complicated form, or feeding their cat.
The response to the nfpSynergy survey, where those who were questioned weren't asked about such distinctions, suggests that the Home Secretary is not using the term 'volunteering' in a commonly accepted way. But part of his job, of course, is to talk up the figures.
Like any other claims for tax relief, Gift Aid has to be checked and audited to prevent abuse. But charities are entitled to be told what the system is, and consulted and informed if there are any changes.
As we reported last week, HM Revenue & Customs apparently decided to tighten the audit system without consulting or telling anyone, and has since acknowledged to to the Charities' Tax Reform Group that it should have been more open about it.
You could argue about whether the old system or the new is fairer. If the tighter system is the one applied in other areas of taxation, there is a case for that to be applied - charities, after all, should not be subject to a more lenient regime over tax matters just because they are charities.
But what has upset people is the covert moving of the goalposts and the impression that HMRC is using every trick in the book to maximise revenue.
It seems that while ministers trumpet what a boon Gift Aid has been to charities - and it has - officials have been busy devising ways to claw some of it back.