Number of times you can be attacked?

I thought this was also limited to twice in the clan war? Someone in my clan has already been attacked 4 times.

If some one gets 1 star on you.. the whole clan can attack you if they want 3 stars on your base. However, each player gets limited to 2 attacks and once a player gets 3 starred, it is irrelevant for someone to attack you again because it counts as only 3 stars therefore, wasting an attack.