Many programmers tempting legal troubles?

Many coders can't help reusing code produced previously - either at the previous employer OR at created by other ppl (open source). Acutally, this should be the way software developed - reuse to save time, cost and productivity. But those source code are also IP (intelectual property), which is why many companies protect it closely.

For me, it's OK to reuse some utility codes, but if copy the entire program source code to reuse, it's no OK.

Source: Careless coders tempting legal troubles?