I am more worried about some dedicated reddit, or 4chan user getting angry than the feds. I'm weird with this because when I write posts I wait 2 minutes, and think how would feds interpret my posts, and is it worth posting that.
I will most likely make a mistake with my anonymity one day, but to have alts increase anonymity wouldn't you have to be good at changing your writing style?
you can't just say that and leave us hangin dawg
Google “stylometry”
A lot of the off the shelf stuff is designed to detect plagiarism for universities, but can do other things too. JK Rowling was writing under a pen name but was discovered by someone using a free program called the “Java Graphical Authorship Attribution Program”