Received one of those messages from the same sender as well, to an address of mine which I published only on Facebook to "my friends".

Each of the included links is unique as you probably noticed. So I guess this is actually a big orchestrated effort to somehow link BM addresses to IP numbers. Very odd.

I wonder where they get the addresses from, and if there is some malicious script on the linked site.

... just as I type, one of those messages arrived on another address of mine which I only shared via email to very few people...

ODD!!!