Since When

When did people begin to use this one? It very nearly drives me to climb a brick wall using my bare hands as anchors.

"Since when did that happen?"
"Since when did you get sick?"
"Since when is it proper to use since when?"

When considering that question, that terribly malformed question, the meaning can be one of two things.
1) "How long has this been going on?" Meaning, the person would like a specific amount of time.
However, the following, I find, is the more likely meaning.
2) "When"

If one is asking for a specific amount of time, "Since when did you get sick?" should be phrased as, "How long ago did you get sick?" or something along those lines.

If one is asking "When?", please for the love of all that is holy, just drop the "Since".
One of the reasons people speak incorrectly is due to laziness, in this scenario be lazy, drop that extra word!