This is the new way of doing it
NSDictionary * resp = [NSJSONSerialization JSONObjectWithData:responseData
options:0
error:&jsonError];
self.strUsername = [resp objectForKey:@"screen_name"];
NSString * strPictureURL = [resp objectForKey:@"profile_image_url"];
strPictureURL = [strPictureURL stringByReplacingOccurrencesOfString:@"_normal" withString:@""];
self.strPictureURL = strPictureURL;