ZLIN50LX PLT AND A BELLANCA 8GCBC PLT HAVE AN NMAC WHILE IN THE SAME WAIVERED AIRSPACE.

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I DEPARTED LONG BEACH ARPT TO TOW A BANNER OVER THE TRACK; WHICH IS APPROX 4 SM N OF RIALTO ARPT. I DID RECEIVE WX VIA COMPUTER. IT TOOK 50 MINS TO FLY TO THE AREA I WAS TO TOW THE BANNER AROUND AN EVENT. PRIOR TO ENTERING ABOUT 10 SM TO NW OF RACE TRACK I MADE RADIO CALLS ON 122.8 TO RIALTO TFC (CTAF FREQ) NOTIFYING RIALTO TFC OF MY INTENTIONS. PRIOR TO OVERFLYING THE RACE TRACK I MADE A SECOND RPT ON 122.8 (RIALTO CTAF) AND ALSO MADE A RPT ON 123.3 FREQ; WHICH IS LOCATED AS THE FREQ FOR ACROBATIC FLT AND STUDENT PLT TRAINING FOR THAT AREA. NO RESPONSES WERE RECEIVED. UPON BEING ON STATION FOR 10 MINS I MADE MORE POS RPTS ON 122.8 AND 123.3 FREQS. AFTER MAKING SEVERAL ORBITS AROUND THE TRACK 2 ACROBATIC PLANES CAME VERY CLOSE AS IF THEY WERE FLYING FORMATION. I CONTINUED TO MAKE MORE RPTS ON 123.3 AND 122.8; WITH NO RESPONSE. BY THE SECOND PASS OF THE ACROBATIC PLANES I DECIDED TO LEAVE THE AREA. I CONTACTED RIVERSIDE RADIO ON 122.1 AND WAS TOLD OF THE ACROBATIC ACTIVITY IN THAT AREA PER NOTAM. UPON LNDG AT LGB I CALLED HAWTHORNE RADIO VIA TELEPHONE. HAWTHORNE RADIO HAD NO NOTAM INFO FOR THAT AREA. SUPPLEMENTAL INFO FROM ACN 710014: WHAT REALLY CAUSED THE PROB WAS THE BANNER TOWING PLANE'S REFUSAL TO LEAVE THE AREA EVEN AFTER HE HAD BEEN CONTACTED ON THE RADIO AND INFORMED OF THE CLOSED AIRSPACE HE WAS VIOLATING. AFTER NUMEROUS ATTEMPTS; I ESTABLISHED RADIO CONTACT ON 122.8 WITH THE PLT OF THE BANNER-TOWING ACFT. HE IDENTED HIMSELF AS SUCH TO ME. HE HAD APPARENTLY HEARD MY DISCUSSION THAT HE SHOULD SWITCH RADIO FREQS TO OUR DISCRETE FREQ; AS HE REPLIED ON THAT FREQ THAT HE WAS WORKING DOING A JOB; AND THAT HE DIDN'T CARE WHETHER THERE WAS A TEMPORARY FLT RESTR OR A NOTAM FOR THIS PARTICULAR AIRSPACE OR NOT; HE WAS GOING TO CONTINUE.