Did you know that farmed Atlantic salmon are "exempt" from the freezing requirement for sushi grade fish.
All seawater raised fish (farmed and wild) can contain roundworm.
The chance of parasites is lower for farmed salmon, which is why it's treated differently. Kind of like saying, "All cheese can contain salmonella" when you're debating between raw milk cheese or cheese made from pasteurized milk. It's an apples to oranges comparison.
Or, a more extreme and ridiculous example, "Driving can cause death, whether the driver is sober or drunk."
![Roll Eyes ::)](http://www.fishingwithrod.com/yabbse/Smileys/default/rolleyes.gif)
That said, I prefer my sashimi wild & previously frozen.