That's not what contact tracing means

from here

Violating privacy is a weird way to look for love in a pandemic. That's not what the information was meant to be used for, and doing that sort of thing is going to create a disincentive to cooperate with something that is very important for public health right now.

An accident, you say?

from here and here

Facebook SAYS their collection of contact lists was unintentional, but how many of these accidents that benefit Facebook at our expense are we willing to believe in? At some point we have to realize that we're being played.