You can use our upload system to unsubscribe activists in bulk, if you have the "Advanced Upload" permission for the group. When you create a new upload, check the unsubscribe box before you click the "Upload & Match Fields" button in the upload window. Instead of subscribing activists, we will unsubscribe any activist who matches an email or unique ID in your uploaded file. The upload will appear in your list of uploads, marked as an unsubscribe upload, with counts on how many activists were unsubscribed.
Note that these activists will stay in your database and be target-able by reports, so you won't lose their action history data even though they are unsubscribed.
You can also resubscribe all activists in your uploaded file, if you have the "Advanced Upload" permission for the group. By default, if an activist has previously unsubscribed from your list by clicking an unsubscribe link at the bottom of your emails or being unsubscribed in another way, if you upload their name again we will not resubscribe them. However, you can override this default by checking the resubscribe checkbox.
Note: Be very careful when resubscribing. Resubscribing people who have unsubscribed may get your emails marked as spam and may result in the termination of your Action Network account. Only resubscribe people who definitely want to receive your emails again.
Finally, you can delete any matching activists from your database entirely by checking the delete checkbox, if you have the "Advanced Upload" permission for the group. This is useful to clear out old or junk data you don't want cluttering up your reports. Be careful with this checkbox -- this operation cannot be undone.