This is unfortunately no joke. Only a fairly primitive technological culture will waste energy and S/N ratio by using coherent signals for communications. Modern radio and TV signals look more or less exactly like static to a receiver that doesn't know what it's listening to, for the same reason that a .jpg or .zip file looks like random data to a program that doesn't know how to decompress it.

So it seems clear that SETI-like efforts will be unlikely to detect any transmissions from civilizations who aren't deliberately trying to talk to us. Only civilizations that occupy the narrow time slice caught between the invention of radio and the widespread adoption of digital computers would be detectable, otherwise.