I don't know how to figure out if the idea we (my friend and I) are thinking of is taken. This is the synopsis: About 2 best friends, Brooklyn & India, who are bored one day and decide to look up their family trees on ancestry.com and find out they're actually fraternal twins. Their story explodes and the 2 small town sisters become famous overnight.
An idea, broadly speaking, can't be "taken." Only the specific execution of it in the form of a story. I don't think it is worth the effort to see if someone has written a story based on the same general idea. Yours will end up very different regardless.
It's always a good idea to check. Everyone knows what happens to those unlucky authors who don't and write a taken idea. Kicked in doors in the middle of the night. Black bags. Whisked off the re-education camps by the Fiction Police. A friend once wrote something that involved a lowly orphan farm boy learning about his heritage and rising to take down the evil empire. He was gone within the week. When he came back, he was obsessed with true originality, to the point that he would scour writing forums and amazon, reading synopsis after synopsis, foregoing food and water until he dropped dead at the keyboard, never having written another word.
