I think it's normal though. The amount of spam we get, I mean. Perhaps we get just a little more than usual.
Other sites just have a system in place to prevent these. I think the site should review how they sign up new members.
For example, random numbers that you have to put in to verify that you are human when you sign up to create a new member. Also, they should limit the number of new members created by the same ip. Like 1 person can sign up per 24 hours and cannot create any new topics but replay with 24 messages per 24 hours for the first few weeks. This will greatly reduce the number of spams we get.