Bollywood megastar Amitabh Bachchan says he handles his social media activity himself contrary to what others assume.

"There is no substitute to personal attention and care ... none ... long may this survive," the 74-year-old posted on his blog.

"Many wonder and ask how many personnel 'deployed' by me for my social media activity... hehehe... None... all done personally," he added.

Narrating why he chose to make the clarification, he said: "Someone was somewhat cryptic and in deep sarcasm, the other day, when they received a birthday greeting from me, in a text never used before and raised an accusing finger... 'You have been caught AB. Your secretary messed up in the greetings you sent... You have never addressed me thus... haha caught you'."

"No, my dear, all that goes out to social media is done at this time of the night and by my own hands... err... fingers," Big B wrote in the blog entry, posted online at 12:41 a.m. on Sunday.