by Michele BirdBuzzFeedBuzzFeed Contributor Warning: This post contains mentions of violence, domestic abuse, and other sensitive topics. The 2000s had some *major* pop culture moments that had everyone raising their eyebrows. From lip-synching fiascos to cheating scandals, all eyes were on these celebs when these stories took Hollywood by storm. Here are the most infamous ones that completely defined the decade: 1. To start, when Ashlee Simpson was accidentally caught lip-syncing on Saturday Night Live in 2004: Dana Edelson / NBCU Photo Bank 2.