The "Search subscribers" page has this searchbox:

Clicking on the labels doesn't toggle the checkboxes. The HTML is currently:

<label for="unconfirmed">
   Show only unconfirmed subscribers:
  <input type="checkbox" name="unconfirmed" value="1">
</label>

In order to work, the <input> needs to have an id which matches the label's for. For example:

<input id="unconfirmed">

I'd like to create a PR to fix that in: