The blue dot is diameter of the humanity's most far-reaching broadcast; a tiny bubble expanding at lightspeed. Anyone/thing outside that dot can't yet know we exist... even if they're listening to exactly the right place and frequency; or even if they care at all.
And that's just one galaxy among countless billions.
A man said to the universe:
"Sir I exist!"
"However," replied the universe,
"The fact has not created in me
A sense of obligation."
-- S. Crane