[RTTY] strange call during the cqwwrtty contest

[KH6GMP]

I was in a run and a strong station that gave only call as "WZA" kept 
calling me and was covering up the other callers. I went back to him 
thinking it was one of those dudes that gives the suffix of his call 
only, I asked for his whole call, kept giving me WZA and so I finally 
qsy'd cuz he wouldnt quit. Never heard him again after my qsy.   I was 
beaming JA at the time.   I was wondering if anyone else got called by 
WZA or if anyone knows if its a commercial station or what?
Thanks for all the Qs in the test, ALOHA 73 de Gary KH6GMP