Well i know once they figure out the telephone numbers are no longer a no-go if your new member with post count less than 10, they will seek other means. But as with any other type of spam, it is a work in progress trying to stop it, and will always need up keep anyway. For me to incorporate this will only add to what is already in place, which works great other than letting telephone numbers through.
dont get me wrong i am not trying to argue with anyone, i just like to debate, mainly because i am learning :P