For those that were as confused as me:
Sealioning (also sea-lioning and sea lioning) is a type of trolling or harassment that consists of pursuing people with relentless requests for evidence, often tangential or previously addressed, while maintaining a pretense of civility and sincerity (“I’m just trying to have a debate”), and feigning ignorance of the subject matter.[1][2][3][4] It may take the form of “incessant, bad-faith invitations to engage in debate”,[5] and has been likened to a denial-of-service attack targeted at human beings.[6] The term originated with a 2014 strip of the webcomic Wondermark by David Malki,[7] which The Independent called “the most apt description of Twitter you’ll ever see”.[8]
P.S.: the comic in question:
Ah yes, Popper’s paradox of tolerance strikes again. (If demonstrating intolerance is the appropriate reaction to witnessing intolerance, how can you distinguish between first order and second order intolerance in the behaviour of others?)