Well ... since the only thing good the DNA for is discrimination - not a single surprise here.

After outside of legitimate research you can use a DNA DB to find:

data about people that are something data about people that are not something

And I am not sure if it is illegal for a non commercial service to require its members to be something.

The problem is not with the database or with the fact that 23&Me collected the data or that 23&me made it available. The problem is that there are people who want to discriminate and would use DNA (and any other available information) for that purpose.