Also people reported sharing the Santa Clara link with others who might want the test (due to having had symptoms). In principle you could have the same problem

Also people reported sharing the Santa Clara link with others who might want the test (due to having had symptoms). In principle you could have the same problem with this survey: call your buddy and say “come on down to Costco—they’re doing free antibody tests”. The obvious fix is to not tell people the results of their own tests. Not sure of the ethics/consequences of that approach.