Someday I may make a list of books that should be required reading for understanding the internet. Most of the serious contenders are about human interaction; Judy Blume's Blubber and Miss Manners' Guide to Excruciating Correct Behavior are almost sure to make the final cut. The only one that's explicitly about the internet is Angela Nagle's Kill All Normies, a fine brief look at the alt-right and the alt-light.
The book is controversial because, like any good book about a conflict, it discusses both sides. In this case, the other side is the identitarian left, and Nagle's observations are too accurate for left-identitarians to forgive.
Her book was published a few months before Charlottesville. She's written a short follow-up, Goodbye, Pepe, that should be the final chapter of Kill All Normies' next edition. Whether the alt-right survives the repercussions of killing Heather Heyer or mutates into something new, Nagle has written the book that anyone who wants to understand the last few year's of online warfare should read.