Satan and the Daughters of Men

Probably Genesis 6:1-4 should not be understood in reference to angels who took human wives, though this has been a common interpretation of that passage. More likely, the "sons of God" in that passage were evil human kings or princes who abducted or perhaps simply raped common women ("daughters of men"). In the ancient Near East, human rulers were often known as "sons of God." Even David was called the "son of God" in Psalm 2:7, in which "begotten" does not refer to his birth but to his installation as king (Ps. 2:6). Rulers were understood to be in metaphoric father-son relationships with their deities. "Daughters of men," by contrast, emphasizes the common or non-royal status of the women these rulers abducted into their harems (cf. Sarai's experience in Gen. 12).
In any event, it is certainly possible that Satan and his demonic hosts influenced the evil behavior of these rulers. There are several examples of similar influence in the Bible (e.g. Luke 22:3//John 13:27; Acts 5:3).