Man I remember the fax bomb. Either huge numbers of black pages to burn through the recipients’ ink toner, or two bits of A4 taped together neatly to form an infinite loop.

The latter was stopped when sending machines got a buffer that images were stored in before they were sent (as opposed to the OG fax machines that dialled the recipient and “live streamed” the pages by scanning and sending at 9600 baud or whatever the handshake was at), and most buffers threw an error when they were full (usually because the sender was taking the piss) and never sent. Shame.