writing illegal characters

I recently got a parsing error reading an XML file which I had produced
programmatically.
The error is org.xml.sax.SAXParseException: Illegal XML character .

The reason for the error, I found out, was that 0xb is an illegal XML
character.

I easily worked my way around the error, by filtering my data before
writing it to XML (which is consistent with my application).

In any case, my question is, given that 0xb and other control characters
are illegal in XML, shouldn't the function
Document.createTextNode(String) check its input and generate an
exception?

Thanks,

	Reuben