Take a look at a comment further up - the relevant point being that millions of pattern-matching calculations are carried out 'for' you, every time something linked to you pops up on line.
And every time a pattern of links-to-links-to-links to things and people pops up online, loosely-related to you, even if the data quality of any individual event or observed correlation is absurdly low.
The hashing functions that do these speed-lookups for matched patterns in the metadata do give false matches from time to time. As in once in every trillion comparisons or so - which, given the sheer number of calculations they run, makes once-in-a-year for a visible error entiely unsurprising.
Nevertheless, I'd go looking for the privacy setting that stops the bastards placing promotional items in your calendar. Even if that dinner at the Ritz was someone else's.
Mind over Meta
Take a look at a comment further up - the relevant point being that millions of pattern-matching calculations are carried out 'for' you, every time something linked to you pops up on line.
And every time a pattern of links-to-links-to-links to things and people pops up online, loosely-related to you, even if the data quality of any individual event or observed correlation is absurdly low.
The hashing functions that do these speed-lookups for matched patterns in the metadata do give false matches from time to time. As in once in every trillion comparisons or so - which, given the sheer number of calculations they run, makes once-in-a-year for a visible error entiely unsurprising.
Nevertheless, I'd go looking for the privacy setting that stops the bastards placing promotional items in your calendar. Even if that dinner at the Ritz was someone else's.