Arms control treaties already do a lot to prevent extreme abuses of real-world weaponry, so why shouldn't they apply to virtual conflicts? The US and China certainly think that makes sense. According to sources speaking to the New York Times, the two countries are negotiating a deal that would set limits on cyberwarfare attacks. It's not clear exactly what this agreement would entail, but it would offer a "generic embrace" of a UN code of conduct that, among other things, bars attacks on critical infrastructure like power grids and cellular networks. At the least, these nations wouldn't be the first to resort to these assaults.