http://www.bmezine.com/tattoo/A50420/high/bmegl053655.jpg油断大敵 is a Japanese phrase that means "unpreparedness is one's greatest enemy" or "he that is too secure is not safe".
But in Chinese, the tattoo above would then read as "lack/sever of oil, big enemy/problem" or "oil crisis".
Perhaps the owner of this tattoo drives a large SUV?
油 = oil, fat, grease, lard; paints
断 = sever, cut off; interrupt
大 = big, great, vast, large, high
敵 = enemy, foe, rival; resist