Servers without world border can be crashed

Hi,
any server (especially creative servers) without set world borders can be led to a crash using abstract high walking/flying speed (which is provided by certain mods) and moving into ungenerated terrain. Most servers attempt to generate the missing chunks but fail to do so as ungenerated chunks will appear faster than the server can generate them. Thus, the server will run out of memory and crash.
(It could be possible to create malicious clients which log in to servers automatically and led it to a crash using the description above)