Celebrities does not en dross brands on honorary basis, they are paid for handsome amount and people tend to follow what they say so it is their responsibility to go and en dross such brands before making through investigation of it. 

It is understood from the way AB, Preity Zinta and Madhuri were given notices..

The brand ambassadors of products are celebrities- film actors or sportsmen. They are in no way expert on the products and they can not be expected to check quality in a laboratory. That is why Food and health authorities are not taking any action against the brand ambassadors. Possibly, they may have to face consumer forums. By posing in advertisements, the products get more attraction. However the consumers also do not belive on words of the brand ambassadors. The consumers have been using the Nesle products for several years or even decades. It could not be unless they were satisfied. So far, no case has been reported of any one falling sick after using Magie or any other Nelse product. In fact, no consumer appears to have made any complaint about bad quality of NEStLE .  The entire matter appears suspicious. Rival componies could be involved. 

Celebrities were given notices for their endorsements by the FDA. FDA after conducting extensive Lab tests found Minerals of high toxicity which cause ailments. If the consumers did not complain of any problem, they might not be aware that their health problems arose due to the ingredients in Maggie. Majority of the consumers are commoners and laymen.