This is an interesting part of the paper; no physical alien invasion required:

6.2 Information hazard
If humanity did not come into direct physical contact with ETI, it could still be possible for ETI to unintentionally harm humanity. This could occur if ETI send harmful information to humanity via electromagnetic transmission. A malicious ETI broadcaster could, for example, send a message containing harmful information that either damages human technology, analogous to a computer virus, or coerces humans into a seemingly benign but ultimately destructive course of action, such as the construction of a dangerous device, [76].

As another example, ETI might send information about its biology, perhaps hoping that humanity could use this information to protect itself against ET diseases or invasive species. However, perhaps such an effort would backfire on humanity if we use the information to create a disease, invasive species, or other hazard. The hazard would be created by humans from the
information received, and the creation could be intentional or unintentional. But if the creation was intentional, then it would be human intent, not ETI intent. The possibility of an intentional or unintentional informational hazard suggests that at least some care should be taken in efforts to detect and analyze electromagnetic signals sent from ETI.
There is one final information hazard scenario to consider. In this scenario, contact with ETI serves as a demoralizing force to humanity, with strong negative consequences. In human history, contact between modern society and stone age culture usually leads to the demise of the more primitive society. Likewise, in the event of contact with ETI, humanity may be driven
toward global cultural collapse when confronted with ETI technology, beliefs, and lifestyle [88].

Even if the ETI are friendly toward us and give us the choice to accept or reject their knowledge, the vast differences between our respective societies may force the more primitive one (ours) into a demoralizing state of societal collapse. For this reason, if ETI do already know of our presence and if they wish to preserve the integrity of our civilization, then they may choose to reveal themselves to us slowly and gradually in order to avoid a calamitous response [23].