WHY WHY WHY WHY doesn't this work!!!

All

So if anyone can explain why

Import-csv C:\Temp\aliaslist.csv | Foreach {Get-Mailbox -identity $_.Alias | Remove-MailboxPermission -User wsht.local\svc.qmm -AccessRights FullAccess -InheritanceType All

Any ideas why this isn't working? I'm trying to remove mailbox permissions for a load of alias' but this isn't working.

I've checked the syntax etc and it's not working still.

Cheers

Alex