No, it's not unusual at all. They employ people full time to do it! And it's not new either, before blogs recruiters contacted people who had a big presence on Usenet or mailing lists.
It is only unusual for someone to confuse it for an actual "job offer".
Not really. I've got emails like that from Microsoft and a ton of other large companies. A guy from Symantec even rang me, said he found me on linkedin, despite my linkedin profile stating not to call me by phone (I don't have my number in my profile, but you can easily find it from linked material). Neither the emails, nor the phone calls mean anything. He still owuld have had to send a CV/resume and maybe get asked for an interview or two before he ever got a job. This isn't unusual at all, its very common.
>It's still unusual for a company the size of Sony to reach out to someone like that.
Uhh, almost all big companies reach out like that. In fact, bigger companies are more likely to need such talent reach out like that because of their brand than random small companies.
What's more is that it's now on Hacker News - so it's bigger news than Sony probably ever intended it to be.