I have looked around Altru, and in particular the Batch Constituent Update and Global Changes, and I don't see a way to delete information from multiple constituents at once.
For example, if I upload a CSV with a list of Lookup IDs, names, and e-mail addresses, it deletes the e-mail address (or address, alternate lookup ID, etc.) from each record in teh CSV. It looks to me like you can only add data via Batch Constituent Update.
Is there something I am missing or is this not an option? Thanks!