I think, there are some things that must be considered about illiterate signature spammers. First is that in many cases it is fine to close some threads that are (or tend to become) spam and not stop users, since if there is not spam thread there would not be no spam posters. Second is that since here is a forum with different sections and different topics, many people may like to talk with each other about things that cannot be valuable in view of others but you cannot stop them. For example many may like to talk about if they have 10$ it is better to buy it or invest it, this may seem a low level discussion, however it is fine to stop others from discussing about it. There are some technical sections in this forum which only technical people are there and you can go and participate in the topic of your interest. Third is that even people who are only spamming can be fine for forum and if they leave here the forum may lose a big part of its users and its popularity. Fourth and final point is that many of people who are spamming after spending some time may be attracted into other sections.