Actually, political donations being public record is a necessary measure to keep cronyism and office-buying at bay.
But, anyone who uses such information to intimidate, harass, or worse should face immediate punishment (upon conviction) that includes the loss of voting privileges for at least a decade - and permanent should be considered (especially for repeat offenders). This would be the penalty for political intimidation. If an organization does it, then everyone registered in that organization should be punished.
And that is over and above the penalty for the actual act.
But, that’s only my opinion.
I think it is safe to say that there is no danger of "cronyism and office-buying" for the 99%+ of the people who gave money to support or oppose Prop 8. Political disclosure laws as presently enforced are a blunt instrument with damaging side effects. Damaging both to individuals and to free political discourse. But perhaps that was the intent, to shut down political discourse in favor of the preferences of the cultural elites. Just as an individual's vote should remain private to protect the democratic process, so should an individual's political donations remain private to protect the democratic process.