In some of the worst cases, the results of a test don't merely cause emotional pain to an individual, but destroy whole families. One man was devastated to learn his beloved daughter was the product of his (soon to be ex-)wife's affair. The couple divorced, their son blamed the daughter for breaking up the family, and the dad called out the son for blaming the daughter. Pretty much everyone but the dog ended up resenting each other. We're reasonably sure they'll have to create a whole new branch of psychology solely to deal with these issues.
Related: The 6 Creepiest Things Hiding In Your DNA
There's No Longer Any Such Thing As Anonymous Sperm Donation
Part of the appeal of wanking it for cash (besides, you know, wanking it for cash) is that it can be completely anonymous if you want. Your broke college ass can sell sperm for some ramen money, and the clinic will make sure that a teen who looks like you won't come bug you in 18 years (probably to beg for ramen money). Or at least, that's how it used to be.
Now, lots of "anonymous" sperm donors are discovering that the contents of those plastic cups from long ago have become living, breathing human beings. And unlike the cup, that human might want to get to know you. The donors themselves don't even need to take a test to be exposed; all it takes is some random relative buying a 23andMe kit for kicks, and you're busted. One donor was tracked down through his nephew, who took an over-the-counter test. So many biological sons and daughters have found him that they created a welcome packet including the man's photo, medical history, and an email address he uses to "reluctantly" answers questions. (Mostly "Do you have this weird thing on your junk too?" we're guessing.)
Whelshsk/Wikimedia Commons"Have you started balding yet? How about now? Now?"