There is a new edition which was published this year (2016). I was able to get it via Amazon - maybe the review is a bit old? I haven’t read much of it so far as I have a few other books on the go but the internet and mobile phones are certainly mentioned.

Edit: Revised edition still has the original author.

Edit 2: Amazon link (not affiliate link): https://www.amazon.com/gp/product/0674737261/ref=oh_aui_deta...

To be fair, he wrote the original as an analysis of how coups d'etat tended to evolve during the postcolonial period; the "practical guide" was just a bit of academic provocation. (As Luttwak admits, he only knows of one coup that actually used his book as a resource, and it failed abysmally.)

I'm totally with you that an entirely new book, post-Arab Spring, is in order, though -- perhaps one half devoted to how to overthrow a government, the other half on how to ruthlessly suppress dissent.