Caller ID:  San Francisco Peninsula Area   <-- dead giveaway this is robocall from a telemarketer / scammer
Caller left no message.

I do not recognize this phone number, so I have blocked it.

I wish the 50 U.S. state legislatures and the U.S. Congress would have the gonads to pass laws that would require telecommunications companies to block robocalls and other calls made by telemarketers and scammers.  I think Canada has such laws in place.  Don't telecommunications companies make enough money, even without the profits they make from telemarketers?