So I'm just trying out Yahoo Web Services and there's something really
simple and basic that I'm confused about. I have an appid and the
example I'm trying does require that I specify an appid but it doesn't
seem to care what it is or even if it is valid.

Looking at http://developer.yahoo.com/java/howto-reqRestJava.html and
the example YahooWebServiceGet.java

The example has
String request = "http://search.yahooapis.com/WebSearchService/V1/
webSearch?appid=YahooDemo&query=madonna&results=2";


I can replace appid with any random string and the example still
works. Shouldn't I have to put in the appid string for the appid I
defined.

This works ...

String request =
"http://search.yahooapis.com/WebSearchService/V1/
webSearch?appid=JUNK&query=pizza&results=2";

And this works ...
String request =
"http://weather.yahooapis.com/forecastrss?appid=MoreJUNK&p=94089";