An update has been released on the WOW servers solving the following problems:

• Regular snowballs will no longer knock down groupmates in a Battleground. This only applies to Battlegrounds. The reason for this is that grouping is forced in the Battlegrounds and players were using the mechanic to cause grief to their teammates.
• "Hardpacked Snowballs" -- specific to Alterac Valley -- can only be used against enemy targets. Again, the reason for this was due to negative player issues caused between teammates in Alterac Valley.