The Jews and many Christians list taking God's name in vain as a very serious sin. For the Jews, the 3rd commandment prohibited their even mentioning the name of God, no matter the context or manner in which it was done. For Christians the focus has been largely on using God's name flippantly or in cursing. Some are so strict in this regard that any expression which can be remotely construed as being an indirect or veiled reference to God are prohibited.
The Hebrew word "shawv" which translates vain in Exodus 20:7 is a noun with a variety of meanings in accordance with Gesenius' Hebrew Lexicon of the Old Testament. It very much conveys the idea of falsehood and wickedness in addition to vanity or emptiness. In our current day English language vain implies to no avail or no purpose, which probably does not do justice to the original Hebrew.
I highly suspect that neither the Jewish preoccupation with avoiding any reference to God by name nor the current Christian denouncement of popular profane expressions capture the essence of this commandment. I think it much more likely that invoking God's name to justify and promote wickedness and falsehoods are the issue to which this commandment points.
In that regard I believe that anyone who references the Bible in support of personal agendas is in great danger of using God's name in vain. Bible passages are routinely used to justify political positions and personal opinions, to label people as inferior, to incite anger and disunity, and to promote self interest. This happens all across the political and religious spectrum, from the most conservative to the most liberal. Whenever we use the Bible as a weapon against others or to self promote, we, by extension, invoke God's name in doing harm and in violating the higher ethics of Jesus.
God is not our bludgeon, to be called upon at our discretion, to beat other people into conformity with personal views, opinions, theology, or politics. Jesus is not a legitimate part of anyone's marketing strategy. Personal gain, profit, and political power are not proper goals for which we can claim God's favor over others.
To my mind, associating God's name with self serving pursuits is vastly more sinful than all the flippant and profane expressions one could ever utter. In saying that, I recognize a certain dissonance or inconsistency for me or anyone who expresses religious and ethical ideas. Those of us who point to religious dogma and divine texts to support our personal opinions stand in imminent danger of crossing a fine line between an honest attempt to persuade and a less honest need to self promote by making one's opinion unimpeachable. If my thoughts and opinions are not logically and ethically persuasive, then any claim to divine approval should not add one whit of weight to my argument.