Increasingly, I'm seeing a lot of insanity with the question mark.
"Could you please do this."
Sometimes, sentences that are commands are phrased as questions without a question mark. People want to be polite and ask others to do things rather than demand that it be done. And "to ask" intuitively means using the interrogative. I understand. But there exists a standard English grammatical structure to accomplish this correctly: "Please do this. Thank you."
"What is the estimated timeframe for delivery."
Sometimes, it's a clue as to the person's tone when they're writing things exactly as they're saying it in their head. They're requesting an answer to an open-ended question and they forget that just because their voices drop, instead of rise, at the end of the question, it's still the interrogative form which still needs to end with a question mark.
I also find it amusing that people will put question marks in where they don't belong, just because their intonation rises.
"I wonder if something is true?"
This is not a question. To wonder whether something is true is a statement, even though you're pondering something you don't know and would very likely ask it as a question.
"When you have a moment? Could you take a look at that other problem."
*ROFLcopter* =D The question mark has now become less of an indicator of a question and more of a voice intonation marker.
It's sloppiness, very simply. Even with all the excuses in the book, the legitimate ones and the illegitimate ones, it's still sloppiness. I have a whole train of thought on my theories as to why people are so damned sloppy, but that's another post.
In any case, please don't punctuate questions with a period and please use a comma to punctuate various auxiliary phrases that belong in the same sentence. Thank you. =)