Truthfully, I would worry if these volunteer sleuthers were given priviledges to roam neighborhoods asking questions, etc., without being thoroughly screened and have some psychological testing done before putting them out in the field. I cringe to think how it could go wrong if you get the "wrong volunteer".
Suppose you're volunteering and get injured on the job...no insurance or much legal recourse. It should be a paying job with some training and benefits, IMO.
Sorry, the more I think about it, I'll just stay here and do my sleuthing with a great crowd, and the peanuts and the beer. Thanks anyways. Call me when you can offer me a paying job!