The ruckus, if it happened on tumblr or facebook , was probably about "Insurrectionary Anarchism As Activism" and "Professional Anarchy and Theoretical Disarmament: On Insurrectionalism" by Miguel Amorós (not an original Attentat piece but a new translation). The latter is a fairly in-depth critique of Alfredo Bonanno specifically--but also Italian IA by proxy--from a Situationist-inspired perspective, while the former is a kind of postscript from Attentat explaining their reasons for the translation and publication of that piece, and relating it to the North American context.
The controversy on the IA point can be boiled down to two related claims: vanguardism, and activism. Though my reading of the piece, especially Attentat's comments, points even more so to ideology--in particular an ideology of action, which assumes the superiority of action (perhaps any action) over inaction. The brief notes on the separation of theory from practice were also an important point for me.
As to the main thrust of Attentat, I seem to remember the journal was also subtitled "the journal of the nihilist position" or similar; nihilism, or critique, or a Situationist influence, seems to me the main thrust of the journal. There are several pieces which take aim at positions other than IA, and more harshly (in "IA As Activism" Attentat say something like that IA is the position probably closest to theirs), but for obvious reasons these haven't raised as many noticeable hackles.
I enjoyed the journal, especially "History As Decomposition," which is a thoughtful engagement with Fredy Perlman's Against His-story, Against Leviathan! as well as Situationist ideas of decomposition.
 If, on the other hand, it was a ruckus on libcom or google+ or twitter, maybe it was another piece :)
[edited for italics]