Maybe there's something sinister here, or maybe Cavium and other similar network chips can be used for sigint, as well as many other things. Basically these are chips designed to look at every packet and can be programmed to take action on them. One could program a chip like this to find all the packages from user X and send an extra copy over to user Y (NSA). It's possible all this tweet means is that these NP chips are powerful and flexible enough to perform sigint. I wonder if this is like saying Intel CPUs can be used to evil things. Or C. Of course it's possible there is a back door, but that seems like the less likely scenario.