They can spam and get the member status, but you can get the member status just as quickly without spamming. Remember, activity only counts the first 4 posts each day. The senior member status is and has always been based on longevity. You do have to already be a member to get senior member, however. This prevents leachers from getting senior member status.

Many times have I denounced the myth that spamming the hell out of the forums will get you senior member status, but apparently you are too new to have caught the last time.