I recv'd the same caller ID in January 2015, I didn't answer it and there was no message left. thanks for all your posts, comforting to know because Yosemite can pull on my heart strings, so tempting to know what the reason is for the call, but I refrained. No suggestions, except continue doing what you are doing and be leery of unknown callers which appears you are already doing and know that others support and do the same, and we support each other with these posts to provide knowledge and information. (I know, not too helpful, but I was thankful for everyone's information to realize what was happening.
I've gotten almost a call a day for the last two/three weeks. I love the call blocking on my Panasonic phone.
My advice, don't accept cold calls from anyone, maybe then poilticians, charities, etc. will put enough pressure on the gov. and phone companies to stop the invasion of our homes.