NBC thwarted Ann Curry\'s attempt to tweet her good wishes to ABC\'s cancer-stricken Robin Roberts last June, New York magazine reported. The magazine said Curry was forbidden to publicly offer Roberts her support because they worked for New York morning programs on rival networks and NBC did not want her perceived as trying to aid the enemy. Roberts, host of \"Good Morning America,\" is a breast cancer survivor battling from myelodysplastic syndrome, a rare blood disorder. She was diagnosed with the disease just as Curry was being eased out of her co-anchor chair on the \"Today\" show.