[1/2] A sign of Microsoft Corp's Bing search engine is seen at the World Artificial Intelligence Conference (WAIC) in Shanghai, China September 21, 2018. Picture taken September 21, 2018. REUTERS/Stringer/File Photo Acquire Licensing Rights BRUSSELS, Oct 9 (Reuters) – EU antitrust regulators are asking Microsoft's (MSFT.O) users and rivals whether Bing should comply with new tough tech rules and also whether that should be the case for Apple's (AAPL.O) iMessage, people familiar with the matter said on Monday. The European Commission in September opened investigations to assess whether Microsoft's Bing, Edge and Microsoft Advertising as well as Apple's iMessage should…