Interesting things in my postbox

On Saturday morning I found nicely printed, illustrated, colourful material in my post-box. The title said "Kuidas ennast kaitsta kemikaali ohu korral?" or "How to protect oneself in case of chemical danger?" Everything is very fine, but I see one problem with it: it is nowhere, not even in smallest print somewhere in the corner, mentioned who has prepared it and who has sent it to me. I guess it might be municipality from City of Tallin, but it's only a guess. In general, I don't like to receive anonymous materials. Perhaps next time someone puts into my mailbox another nicely printed, well illustrated, colourful material with different title, for instance, "How to make a plastic bomb?"