Just as an aside: this guy isn't the voice of the gecko, he's the narrator for the commercials. And Geico fired him right after this came out unfortunately, failing to note that the people he prank called then found out his home number and address, distributed it on the internet, and encouraged people to make death threats.
According to news reports, he left his number with the message.
I've been kind of curious what this means for other places one might leave messages for an organization: Do they have to disclose they might use your voicemail for something? If they didn't, in theory, he might have a case for legal action.
Of course, he's getting a lot of attention for FreedomWorks putting it out there and its members who felt "threatened" deciding that the proper response is to threaten him with death. On the whole, it could be a positive for his career.