Copenhagen Public Libraries. Roughly translated (I think) the poster intro's say "Discover the other side of..." Bottom tag line ? (the machine translation was sketchy here) - "Copenhagen Libraries - it's not what you think"
From Flickr photo pool: (translated here)
"With thought-provoking - and maybe provocative - posters at the Copenhagen town life and at the libraries and with the slogan: "Københavns Biblioteker-alt hvad du kan tænke dig" /bibliotek.kk.dk go we new roads with this Brande-text: "At the library we have everything what you can imagine: You cause peace to think carefully and give this a thought. You get time to come ahead, come to the rear and come again. Space for that you may be yourself, because here is nobody who decides what you have to think. You are free to get lost in your thoughts - and think of something, you have never thought of before."
See all the posters in the Flickr pool - way cool!