My guess is that in this particular instance the issue is that it is a cell phone. I know almost all cell phones now do a whole lot more than be a phone, but most schools have policies against using phones because they can and are used a lot for cheating and generally the latest generation of passing notes that we use to do in school. (I am not implying that your DS would use it improperly, just that there are many that do.) I know in my class I allow students to use phones for note taking and calculators and even research as long as they can then show me at the end of class that that is in fact what they have been doing and that they have not been just playing games or texting friends. I have had to explain myself to other teachers and admin. about my policy, but I know many other teachers who do not feel they can keep control of a class if cell phones are allowed for any reason.
It would be a lot better if more teachers would allow more technology for kids that need it, but depending on the age of the teacher, there is also the issue of being techno-phobic, and afraid that the students will do something that could get them (the teacher) in trouble.
