Why won't people graffiti?

I thought it was a glitch that visits from neighbours didn't generate FPs unless there was graffiti involved until I did a bit of trawling thru the forums. I would have thought that, by now, most higher-level players would have figured it out.

So yeh, I'll always look for graffitiable buildings in my neighbours' towns; the favour is generally repaid. Apologies if I occasionally miss one.