Legalism is easy to observe in modern communities of Orthodox Jews and somewhat less easy to pin-point amoung Evangelicals. This is partly because the rules about public worship have been expressed as sociological patterns of behaviour. For example show restraint (or be exuberant within certain boundaries), attend group activities regularly and be disciplined in your habits. However our public expression of personal piety shouldn't be bound by either Orthodox Jewish style rules about Sabbath observance or Evangelical group behaviour. "Therefore do not let anyone judge you by what you eat or drink, or with regard to a religious festival, a New Moon celebration or a Sabbath day." (Col 2:16 NIV) As we respond God's grace and grow in maturity we're no longer bound by these rules, there is an extraordinary freedom here.
"Since you died with Christ to the basic principles of this world, why as though you still belonged to it, do you submit to its rules: Do not handle! Do not taste! Do not touch!" (Col 2:20-21) Some modern evangelical taboos include: don't gamble, don't look at nudity, don't swear and don't get angry or behaviour erratically. The danger here as the Apostle Paul points out is that the psychological pleasure gained from, for example, not looking at porn becomes greater than the desire to respond positively to the living God. "Such regulations indeed have an appearance of wisdom, with their self-imposed worship, their false humility and their harsh treatment of the body, but they lack any value in trestraining seual indulgance." (Col 2:23)