I hope that POET is used for peaceful purposes, to advance our race, to help us explore previously unattainable subjects.
The likelihood is that like with ANY technology, it will be used for good and for ill equally. The ethical implications are always considered after the fact when bringing a new technological capability to market.
For example, there may have been some forward-thinkers who could have predicted what the PC revolution would mean for American workers, but even if they had put their concerns forward to Bill Gates in the early 1980s, it would not have changed what Microsoft (or Apple) did. Their focus was on the productivity of those who could afford to purchase the tools they were developing, not on the wider picture that included the possibility that those early adopters were effectively financing their own removal from the work force.