Even if imitation is the sincerest form of flattery, it never hurts to cite your sources or acknowledge your inspiration. At least, that’s the position that Sleigh Bells has taken on Demi Lovato’s latest song. The Brooklyn duo called out the Confident singer on Twitter for borrowing from “Riot Rhythms” and “Infinity Guitars,” two songs off its debut album Treats. The band was “flattered” by the sampling, but pointed out that permission was not requested.