You can shift-select to select multiple items in the portal. Click on the title of first item you want, scroll to the last item, hold the shift key and click on the title of the last item.
Shift-click to select multiple items is great. It should remain.
But a Select All button is so much quicker and more elegant of a solution! I still think it would be a great addition that many many users would implement, especially because they'll see it on the top bar; and there's no room for a sign that tells users: "oh by the way, you can click the first item on the list and then scroll down to the end of the list and shift click on the last item on the list and this will select all the items in the list."
