If there are more and more users (and/or bots) who disobey these good and reasonable rules, it will be bad for the forum and its existence will be not easy. In the worst case, there is a solution -- just stop the new registrations (once you have enough persons, who are able to create quality content).
I think this function is available in every forum. Another quote from that one (I'm not sure what was the reason for this, but I quote it as an example of a good solution, in case there are many bad users and/or bots, and when it's very hard or impossible to deal with all of them like you ban them, but they come again, etc.) --
Sorry, new registrations are currently suspended, please check back again later.
Also, You can refer to this topics:Registrations are currently suspended,Any news about registrations will be attached there.
An easy and working measure.