Storing the IMEI from an Android phone on an American Server.

Is it legally OK to store an SHA1 Hash of a user IMEI on a server?

I have asked the user for permission before sending the IMEI.

From stackoverflow

• As long as the operation is not reversible you should be fine. I've had the same kind of issues in the past while writing an application that needed a unique ID from the user to be stored in the server. After putting it past through legal it was fine as long it wasn't possible to get from the hash back to the exact user.