Everything has a price, even the top Twitter handles, and if somebody does not want to sell then they may be forced to relinquish their account.

“We have a marketplace which allows the sale of Twitter handles,” says Philly, a subversive marketer who founded ForumKorner, an online gaming forum. “Unlike some websites, however, we do not allow the sales of stolen accounts that some people phish, or hack, to obtain before reselling them.”

It’s the same across the whole of social media. Last month a teenage boy was given a £5,000 cruise in exchange for his Snapchat username while accounts on Instagram are sold openly on online marketplaces.
https://www.theguardian.com/technology/2018/apr/17/selling-twitter-handles-big-business-identity