Federal law enforcement officers or private contractors shall not seize any photographic equipment or their contents or memory cards or film, and shall not order a photographer to erase the contents of a camera or memory card or film.
The OP is using GAFE, Google Apps for Education. It's basically the same as the commercial offering. Students don't create their own accounts, the district likely has a process in place that automatically provisions the new accounts using something like Google Apps Directory Sync or a 3rd party app that uses the Google Accounts APIs. Kids / employees go to sign in and it Just Works. (TM).
(Source: I've implemented GAFE / GADS at a K-12.)