Because Anonlang is trying to blur the line between code and data, there is the possibility of a security concern.
In Anonlang, if data can be saved, then it seems likely that code can be saved also. And, if there really is no theoretical difference, then data/code can easily be sent to other places also, or even received remotely
Programming languages that don't have the ability to alter their own code can be more secure than languages that have the ability to alter their own code.
This is going to be another trade-off that has to be carefully considered.
Having said that, since another idea of Anonlang is to try to have everything as change-able, kinda like plug-in style, there would probably be a way to make code non-self-modifying or allow it.