How did they get hold of my mse email and username?

mr_fishbulb

This doesn't look good. It's safe to assume that your MSE password may have been compromised too. If you use the same password to log into other sites (especially if your username is the same) then you should seriously consider changing your password on the other sites.

Glad

if you can post re the above in this thread only it will keep all the info in one place for the MSE team to look at, the MSE team have posted there