All nuts, seeds, and grains contain phytic acid, or phytates.
Phytic acid is a concern for people who get most of their nourishment from these sources, since phytic acid may interfere with the absorption of some nutrients like iron, zinc, calcium, and magnesium. Phytic acid also inhibits certain enzymes needed for protein and starch digestion. This is why vegans and vegetarians who eat phytate-containing foods more often will try to neutralize the phytate by soaking, sprouting, and fermenting these foods.
For nuts the preferred technique is overnight soaking followed by gentle dehydration. RAW nuts contain an enzyme called phytase which breaks down phytic acid after being activated by soaking and sprouting. Non-RAW foodists may also roast their nuts for the maximum removal of phytic acid. These precautions are only mandatory for diets dependent on phytate-rich foods, especially when the diet is low in calcium and Vitamin A (usually from dairy and animal products). Also, phytic acid only inhibits absorption while it is in contact with foods, so snacking on a handful of nuts in between meals is unlikely to cause any problems.