What unforeseen problems could your solution to a problem create?

This is primarily a question posed to coders and optimists alike who tend to think of all the positives and best scenarios. But everything we bring into existence has equal potential whether we like to face it or not, to do harm. This of course is not meant to discourage makers from doing what so few are even motivated to start. But rather to flip to the other side of the coin, and reveal what so many of us are ignoring at the peril of perpetuating a wack a mole of problems that exist in this world.

Comment below! Think about the best case scenario of your app or solution succeeding. Now consider what "evil/bad" does that enable?

Try avoiding obvious general things like "It could be a time suck". What specific problem could only your solution introduce?

Example:

1. Connect billions of people on a social network
2. Foreign governments are able to psychographically target populations with political ads.