It is recommended that all teachers use a school-owned, school-managed media content management and hosting service rather than a personal one, that is shared by the school for a number of reasons:
it contains all media content that is (strictly speaking) owned by the school from a copyright point of view
it is completely searchable so that anyone should be able to find all the school's media content belonging to the school
any teacher can use any of the content created by other teachers at the school
if there are any issues with media that has been posted, it is easy for anyone to find and correct the issue.
In short, using your own account limits the availability of the school's media to others and breaches DoE copyright.
For more information, go here: http://www.smartcopying.edu.au/