Get a temporary, throw-away email address to use for your job hunt. (This helpful advice was given to me after-the-fact by a fellow member of the Bridge.edu job board.)
Why? Because you will be innundated by a horde of job "suggestions" from commercial job boards, none of which are remotely relevant to your search. The emails proliferate almost faster than you can unsubscribe.
I suspect the one commercial job board I updated was the initial culprit, selling my records (old and new) to others. However from the wording of some of these "offers", I believe that some of them originate with my LinkedIn records, which I had thought were relatively safe.
The problem is orders of multitude greater than it was a dozen years ago when I last looked for a job.
In some ways the internet and social media are great tools but in other ways, not so much.