TikTok Stars Believe Trump Wants to Ban App as Revenge for Trolling Him

President Trump says his threat to ban TikTok is about China stealing data, but that's just a cover story ... at least according to TikTokers who think he can't take a joke, and simply wants revenge.

TMZ spoke with Mary Jo Laupp -- AKA TikTok Grandma -- and DeJuan Booker, a couple of proud TikTok trolls who've been on a mission to derail Trump's presidency along with his businesses ... and they think he's striking back with the potential ban.

Mary Jo made the original TikTok encouraging people to register for Trump's Tulsa rally and then not show up -- a battle cry that spread like wildfire among teens and K-pop fans. She thinks believes he's still miffed about how it affected his rally, and all his vigor toward banning TikTok is just a grudge.

Laupp says even if he does go through with the ban, it was worth it to show how Gen Z'ers can impact politics -- and hopes it motivates them to hit the polls in November.

Meanwhile, DeJuan -- the leader of "Gen Savage" and creator of multiple Trump pranks -- says Trump's revenge plot won't work, because his community will simply move to other platforms if the Prez bans TikTok.

And, he adds ... you better believe they'll keep speaking out against 45.

DeJuan acknowledges his Trump pranks may be seen as petty, but tells us the whole purpose is to let Gen Z know their voice matters and when they come together ... they can make a difference.