if by "centuries" you mean "
A century" then yes. But this argument is addressed, and seemingly refuted in the article I posted:
But maybe we haven?t yet blown our cover: Brin doesn?t accept Shostak?s assertion that ?they? already know we?re here (sometimes called the ?barn door? issue). Shostak is too generous in calculating how visible we are from hundreds (or even thousands) of light-years away, says Brin, who holds a Ph.D. in planetary science and has done consulting work for NASA. Terrestrial radio and TV signals, from I Love Lucy to whatever is leaking out of Vandenberg and Guant?namo, are relatively weak. Furthermore, electromagnetic signals fall off in proportion to the square of the distance (and ETs, if they exist, are pretty darn distant). Most likely, Brin says, they have no idea we?re here?and they won?t, unless we start beaming powerful, highly directed signals in the manner that Vakoch proposes.