For a lonng time hardly anyone in Timbuktu has been able to read these documents. If you can't read it you can't find sacrilege.
Thats not quite true; any person going to Timboktu, can see and read (if has knowledge of arabic or the squiggly writing) the manuscripts.
Unfortunately, any islamist that can’t understand the writing (and most of them can’t read) will consider it sacrilegious and will destroy it.