Happy Father's Day! It's that special day of the year where we tip our hats to dads around the globe thanking them for everything they do, and rockers are no different. Many musicians are checking in on Twitter today to share their gratitude and well wishes with their own fathers in addition to all dads in general. Check out what rockers like Nikki Sixx, Nickelback, Disturbed's Dave Draiman and many more had to say below to all the dads out there.