International Socialist Network. They recently voted to name their journal 'Cactus' (they probably shouldn't have made it a public poll). http://www.cs.cornell.edu/w8/~andru/...6b6392dae13949
To be honest, I had to google what 'ISN' is. So no. What is their (Irish Socialist Network, right?) relation to Cactus, by the way?
Is your username not an ISN reference then?
