Sony Music and Warner Music are suing Anthropic, Dario Amodei and Benjamin Mann for 'one of the largest and most blatant ongoing thefts of intellectual property in history.' It was filed late last night, and they made no announcements, so the press has not picked it up yet. Quoting from the filing (whoever wrote this went all out): 'Plaintiff Music Publishers, a group of the world's leading music publishers, bring this action to hold accountable the culprits behind one of the largest and most…