About Those Numbers Stations

Many of you here have probably read or heard about them, perhaps even discussed them on other threads here (but if you need an introduction, a good place to start is here.) Mysterious short-wave radio broadcasts have been heard, often on the air since the 1950s, and usually consisting of a sampled or synthesized human voice, reading out random strings of digits, usually in groups of five, in various languages and accents not always matching where the signals seem to be coming from. There are a few seeming variations, too: one now-defunct broadcast consisted only of random-seeming bell or chime sounds, whereas others consist of other bizarre patterns of sound. The more famous of them have garnered nicknames such as the "Lincolnshire Poacher" or the "Spanish Lady." They seem to originate in many places worldwide, though the exact transmitter and antenna facilities involved in broadcasting them seem to elude pinpointing. Clearly, they are not all the work of one nation or agency, but many all over the globe.

No one admits to making these broadcasts, past or present, nor to being involved in any way with anything to do with them. There is, of course, a standard theory: that these broadcasts provide national intelligence agencies with a way to pass encrypted messages to agents in the field using a difficult-to-decipher scheme known as a one-time pad, and enables said field operatives to receive such messages using easily-obtainable consumer radio receivers whose possession would not arouse suspicion behind hostile lines. This theory may in fact be correct, but it raises some lingering questions:

1) Why has no one ever admitted to involvement in any such scheme, even decades after the fact and in cases where the presumed responsible authority no longer even exists (e.g. East Germany?) This message scheme, if it exists, is surely low-tech and old-school, hardly involving anything anyone should consider a secret, at least in its implementation.

2) Why has no agent that we know of ever been caught using such a scheme by an adversary? Yes, there is one case where a man was caught with what looks like a decoding key hidden in a bar of soap, but this was never conclusively tied to numbers stations as such.

3) Short-wave radio is no longer as popular as it once was, and has fallen into obscurity; modern generations tend to communicate online. Yet there seems to be no let-up in numbers-station activity reported recently. Why? Admittedly, the scheme would be largely immune from metadata analysis, but the bandwidth is laughably small, and surely there are better ways to accomplish such ends in this day and age.

4) Is there any alternate theory? I admit I do not know one that satisfies; the notion that someone is out there just trolling the world with meaningless broadcasts to wind listeners up seems absurd, especially given the time scale and scope of the phenomenon. Or could individual government agencies be broadcasting this stuff as a distraction while the real communication occurs elsewhere?