I Like Rock Music

Isn't it weird how two totally different songs can sound identical? I'm sure each and every one of these were unintentional but here are some rock hits that sound similar, if not exactly the same as another song...

"Young Lust" by Pink Floyd and "Toys in the Attic" by Aerosmith (opening riffs):
[youtube=https://www.youtube.com/watch?v=-bWdWZLSTio][youtube=https://www.youtube.com/watch?v=mO-p_eSe8yU]

"New Fang" by Them Crooked Vultures and "No Tomorrow" by The Blackouts:
[youtube=https://www.youtube.com/watch?v=S7_vH3H8LPI]
[youtube=https://www.youtube.com/watch?v=w6qdPP0cMeU]

"Childhood's End" by Iron Maiden and "Piece of the Action" by The Babys (opening riffs):
[youtube=https://www.youtube.com/watch?v=EuHAE5TvW0E]
[youtube=https://www.youtube.com/watch?v=8aRhtSeXegI]

"Warning" by Green Day and "Picture Book" by The Kinks:
[youtube=https://www.youtube.com/watch?v=eebfMFzJHNs]
[youtube=https://www.youtube.com/watch?v=B7encWb7lNQ]

Feel free to share some that you know of!