There was one rule change that passed at the NFL owners' meetings that the Green Bay Packers did not vote for. Team President Mark Murphy, who speaks for the owners of the team, voted against the rule that changed the classification of crack-back blocks. It is now considered a foul on a defenseless player, meaning it's a 15-yard penalty.
Said Murphy, to Rob Demovsky of PackersNews.com:
"I still think the block will be able to be made," Murphy said. "But the target is from the knees up to the shoulder."
The Packers run a zone-blocking scheme, so they regularly make cut blocks, but there is a big difference between legal cut blocks and crack-back blocks. Quite simply, you can't block guys below the knees and you can't block from behind. These aren't unfair standards and it shouldn't change how the Packers play. They do a good job of making clean cut-blocks, and even though Murphy voted against the rule change, I don't see any reason to believe that this will alter the way the Packers play.