There's something even more aggravating for me, however: commas inserted where they shouldn't be. I mean, first of all, why waste the effort? Second - it makes your writing choppy. But there's a trend going on among independent authors, specifically with the word "but" and commas. See how I started that sentence with, "But..."? And do you notice a comma in that sentence? Do you see that the comma is not immediately after the first word?
Many people were taught by junior high middle school teachers that it is incorrect to start a sentence with the word "but." That's not the case, but it's a good thing to avoid overuse, so it's not terrible to write with this idea in mind. However, then some idiot English teacher decided to completely oversimplify its usage, telling students they could use it, but only if a comma followed.
That is so beyond wrong it makes my head spin. The only time a comma should follow the word "but" at the beginning of the sentence is if an independent clause follows (and then is closed by a subsequent comma). Want an example? Look at the title of this blog entry.
Be kind to your commas. Help them find jobs where needed, and don't stress them out in jobs they won't get paid for. Okay?