I heard it Through the Grapevine

I don't know why, but I find it surprising at how many things are found out through the grapevine. If you think about it, take a good hard look at all the things you find out first from the rumor mill. Affairs, corporate take-overs, murders, and other crimes. I'm sure you get the picture. Of course it's not enough for proof of anything, but enough to get you thinking. And of course starting to look at the bigger picture. But you admit this is the part where things tend to get started. For example, in the case of a suspected affair, this is where they would perhaps choose to hire a private investigator. If someone suspects something is awry, if they are a concerned citizen, this is perhaps where they would call the cops and give them a tip. Or perhaps it's nothing more than someone biding their time. Keeping a close eye on things until they can catch them with something real good. Like their hand in the cookie jar.