Change the Texting Limits
You need to increase the number of people you can communicate with in a text. Some people use this for business or for organizational groups that have more than 10 people they need to be in contact with. Your reason about spam is a joke. We have a closed group that your number needs to be added in order to receive or place a text. I need to be in contact with people at work, I am also involved with my local school PTA's, school sport teams, school booster club, a travel softball team, and a local community parent group. When we need to have a meeting or we are planning an event it is much easier to text a group rather than call the individual people or e-mail so everyone is on the same page at the same time.
I have been an AT&T customer almost since the beginning of cell phone useage and never had spam texts. Sadly, will be leaving our family plan behind to go with any other service that has does not cause these problems. I have polled many of the people in my groups and the only people with this problem is AT&T customers. The Verizon, T-mobile, Sprint carries are not in this situation.