Hanson — Zac Hanson, the one with the good hair, specifically — has SLAMMED Justin Bieber’s music.
You usually see people dragging the artist himself instead of his art, but Zac clearly has zero chill when it comes to bashing Bieber’s songs, and Isaac isn’t far behind.
At least they’re not throwing things at Bieber … but did they go too far?
You gotta remember Hanson. They…