On: Wow signal

[blueskin_]

>for example a reaction motivated by religion or paranoia.

It's also possible they might simply want to quarantine Earth as wars, religion and poverty are still present, and they wouldn't want them to spread to the rest of the galaxy.

[Udo → blueskin_]

Let's file that under paranoia since we're in no position to impose our "values" on the rest of the galaxy. ;)