Spamming old Databases
Three after taking over O2 in Ireland spammed both ex O2 customers and those that O2 had stopping emailing as they had asked for no more.
Three should never have been allowed to purchase O2. But that is another story.
Anti-spam legislation seems to be pointless. But the underlying problem is how email was designed in the first place. Step 1 should be "xyz" wants to add you as a contact, Yes/No. If No is selected then every email from "xyz" should be bounced from first SMTP / MX not under "xyz" control. Implementing this with the current systems is impossible as "spoofing" an approved contact as "from" is trivial.