WOW, we like to argue dont we!! Any species of T that has the propensity to become invasive should be illegal to import or breed. In terms of specimens already kept in captivity, that is where they should stay, possibly in a conservation/education type park or with the original owner under governance of the powers that be, as difficult as it would be to moderate. Futhermore there are species which are not illegal that could become invasive e.g.
Stromatopelma calceatum and in addition most T's based on average stats would survive happily in KZN.
In order for effective control of the hobby conservation bodies would need to do extensive research to eliminate possible invasive species, we all also need to remember that its not only the spider that can become problematic, but also the smaller organisms they bring along with them. Its a tricky situation that is complicated to fully understand due to immense numbers of variables, for example one argument I have voiced and heard before is the issue of humidity, most T's require high humidity yes; but humidity under the ground is different to humidity above it, especially if there is moisture available; most burrowing Ts stay in or close to their burrows all the time, except to mate, so it doesnt take a serious boffin or leap of the imagination to figure that a T such as a
Brachypelma sp. could survive in a river bank type microhabitat in an area that one wouldnt assume it would survive in based on average climatic statistics. I could go on and on and on; sadly and thankfully for this hobby alot of the facts we have today werent available before and it was/is impossible to stop the import of T's into SA, if kilos of coke can get through so can spiders!!
My point is we as members of the hobby have a responsibility to the enviroment, hobby and each other to at least attempt to obey the restrictions put in place by natcon bodies, even if we think they are ridiculous. E.g. T's are illegal in the western cape but copper heads which come from the same climate arent?? If the hobby gets out of control in the eyes of the authorities they are unlikely to finance or accept any research/pleas to extend the hobby and much more likely just to make it illegal to keep any at all. Whilst it would be expensive to enforce the law, it would be cheaper than trying to regulate the hobby if hobbyists are non-compliant. To those members of the hobby that are profit driven, if there is no hobby left due to your unscrupulous behavior

you will make very little profit.
It is a privelage to be able to keep, study and interact with these amazing life forms, not a right. It is important to also remember that they are just that, life forms and they should be respected, otherwise eventually they will land up as genetically warped as other pet animals, e.g. persian cats with no tear ducts