> "may view it"

If we assume that "may" here means "could somehow" and not "is authorized to", the legal action after revelation seems correct as written (ignoring whether the person viewing it has any relation to the person being threatened) unless the law gets struck down as unconstitutional. The question is only whether Anthropic should or should not report it.

> "If I write ... It was clearly intended to be a private note!"

The law as written doesn't appear to distinguish about intent of privacy. Also, if you're in the habit of writing notes to yourself, I guess maybe don't write down the one that says you're going to shoot up the sheriff's office.