Don't listen for aliens because they will just tell us lies, says very strange person

A complex message from space may require the use of computers to display, analyze and understand. Such a message cannot be decontaminated with certainty, and technical risks remain which can pose an existential threat. Complex messages would need to be destroyed in the risk averse case.

There are several possible threats from an ETI message. On the most basic level, a message might represent a statement like “We will make your sun go supernova tomorrow”. True or not, it could cause wide-spread panic. More realistically, a longer text could have a demoralizing cultural influence. For example, it is debated whether the Roman Empire was destroyed by the bible (McGiffert 1909).

What, even the aliens are sending us fake news now ? Don't we have enough of that ourselves ?

Current research indicates that even well-designed boxes are useless, and a sufficiently intelligent AI will be able to persuade or trick its human keepers into releasing it (Armstrong et al. 2012; Dawson et al. 2016).

Quickly, there could be a community on Earth in favor of letting it out for religious, philosophical etc. reasons. If the AI promises to cure cancer, or offers a message of salvation, a cult could form. Maybe (or maybe not) a majority of the population would be in favor of releasing the AI. Should, or even could, a democratic government work against the majority of its people? Dictatorships are unstable and eventually overthrown; the AI will be eventually released.

With a non-zero prison escape probability in any single time period, the AI will be free at some point of time. Then, the worst possible result would be human extinction or some other unrecoverable global catastrophe (Bostrom 2014).

Yes, this is definitely a very important thing to be worrying about. Definitely.
https://arxiv.org/abs/1802.02180