Microsoft is looking to sue almost 200 people for sending millions of junk mail messages.
The firm filed eight lawsuits and claimed that defendants, including the notorious Florida spammer John Hites, hid themselves using false identities and deceived recipients.
Microsoft is looking to use the CAN-Spam against the defendants and could win up to $1 million in civil fines from each one.
The firm is flighting more than 80 spam cases around the world, 51 of which are in the US.