People are ridiculous. If you don't like parts of the summer reading programs your library is offering, don't allow your kids to attend them. Sure, make sure your "children [are] being taught the right things", but quit trying to raise everyone else's children. Besides, based on this list of possible ideas for the nationwide summer reading program, I'd say only a fraction of it could be seen as objectionable anyway. Do you really need to threaten to picket over that?
Besides, huge objections over tarot cards and horoscope readings? What teen (or actually, pre-teen - I would argue kids find out about this stuff much earlier) doesn't mess with a Ouija board, try to put their friends into trances, pretend to read tarot cards, or stare into a mirror to summon Bloody Mary at some point? I was raised by pretty strict Presbyterian parents, and I managed to do 3 of the 4 things in the previous sentence (those Ouija boards, they are elusive), and more that I can't remember, all by 3rd grade! So even children in religious families experiment with that stuff. What you should be more concerned about is whether or not you've done a good job raising your teens to know the difference between nonsense and reality.
I completely agree with Media Specialist Christina Connell when she says the library is “sending the wrong message to teens, who will feel that they are not important enough to fight for, and to the church groups, who will only be empowered to launch further crusades against books.”