Dumb ass? Douche bag? Hey now, let's not get rough! I just took your arguments to their logical extreme. :)
You don't have some right to know who anyone is. Privacy is everyone's right. So I know that can't be your argument, as you're in favor of called id blocking correct? You seem sick of "unknown caller", so I'm not so sure how you stand there.
I can tell you I'm Daffy Duck (ignoring copyright issues) and present myself to you as such. Whether or not you have some expectation that this should be true or untrue based on the medium of this communication has no bearing. What's WRONG with saying I'm someone I'm not with the full intention of having you believe this to be true if I'm not trying to commit a crime against you? Nothing, and that's how it has always been. I can send you emails or postal mail with completely legal non-fraudulent content posing as someone I am not or posing as no one at all because I choose to do so anonymously. This is my personal freedom to do.
It may be your "private phone", but it's my private phone too. We both have a similar private connection to the internet, should I have to reveal my identity to you when I email you? Arguing that this is different seems illogical to me. You can easily jump from phone calls to emails in the same fashion. Both are simply communications sent over private networks neither of us own but pay a fee to connect to. You simply have come to expect or desire no anonymity from phones while expecting that this exists on the internet because it's a "public forum"? Not buying it, because for one most of the web isn't a public forum. It's privately run forums where the owners can do as they wish. But also because I don't see how your assumptions on the validity of people's identity should enter into this at all.
Back to phones for a moment. You don't own the phone network nor do you own my telephone termination where I can set my caller id (a feature I pay for and should be able set). You don't HAVE to have a phone and you don't HAVE to have caller id. Caller id is merely a convenience feature, it's not an authentication scheme as much as you'd like it to be.
This law is simply making a class of criminals we don't NEED. Why should we make a criminal out of someone for inconveniencing you? I just don't see the need for such a silly useless law. There have been examples of numerous USEFUL and non damaging uses for caller id "spoofing" which you have snubbed most of. This is hardly a crime and I'm not sure who this is aimed to protect other than people who don't want to be inconvenienced.