I suggest you read the Portal FAQ - Blam and Protection Points
To receive blam and protection points, you must vote on movies in the portal that are under judgment. If a movie is under judgment, the name will appear in grey at the top of the "Fifty Most Recent" column in the portal. Then you must watch the movie that is under judgment, until the voting bar appears. Once the bar appears, you may vote on the entry to be blammed or protected. To blam an entry that you think is not good, vote 0 or 1. If you want to protect an entry, vote 2, 3, 4, or 5.
If the entry is deleted, and you voted 0 or 1, you will receive a blam point. If you voted 2, 3, 4, or 5, and the entry is saved, you will receive a protect point.
Entries are deleted if they fall below the listed score with the listed amount of votes:
150 votes - 1.0
175 votes - 1.25
200 votes - 1.60
You can see a list of all the blam/protection levels and voting power boosts per level here.
You can find a list of the top 50 blam / protectors here, and a user made b/p list here.
You can find out more information on this system here.
