Which is the exciting part. Year by year our planet hunting methods improve. At first we could only see the largest gas giants close in to their star. Then large rocky planets. The day is coming (I'm sure) when we'll strike gold, figuratively speaking.
Should we then beam a message there once found? That opens a whole other door to a discussion. Remember the Conquistadors and native people of South America. Or for that matter the native North Americans and other European powers. The only thing that could protect us are vast distances... perhaps.
I recently read the synopsis for an older sci-fi book (sorry I don't remember the name, they were cephalopods) where aliens detected our transmissions and took from them that whenever we encounter aliens we were violent. To protect themselves and waltzed right over and wiped out humanity on Earth and throughout our system. Scary thought to be judged and made extinct because of Hollywood and bad writers!