When most "libertarians" - these almost always being of the lolbert variety - hear the word 'gatekeeping', they almost instantly recoil in either fear, disgust, or both. This is almost certainly due to their desire to become one of the "cool kids" on social media and/or political activism, which by necessity entails that the political movements extolled by such individuals must become popular and "mainstream" in the political zeitgeist. This, of course, means that such movements need to be large in size and approachable to even the most centrist of individuals, meaning that gatekeeping - defined by the author as 'the act of filtering information and individuals to a movement as a means of preventing the co-opting of its message' - is viewed by such individuals as an anathema to their goals. It is because of this that such people should be promptly ignored when it comes to their views.
In terms of why gatekeeping is necessary, this can best be explained through an allegorical example of defending a castle. The most well-defended castles, even though they remain in contact with their neighbors through trade relations, were those that kept their gatehouses well-secured and well-manned throughout the year without any gaps. Those castles were those that stood the test of time for not just decades, but centuries even. Meanwhile, those castles which had neglected to keep their entrances well-guarded during times of both war and peace were those who fell to their enemies in various ways - be it their water supplies were poisoned, a spy sabotaged their defenses, or even gunpowder was snuck into their walls and detonated. Such castles rarely lasted long, even in times of peace, as there never was and still never is any such thing as being wholly without enemies.
The allegory above is easily able to be compared to the current state of the Liberty Movement. Even as you read this, the lack of initial gatekeeping for the movement - especially on social media platforms such as Facebook, Twitter, and Instagram - has done lasting damage to the message that was put forth by individuals such as Murray Rothbard and Ron Paul. Because of a lack of keeping individuals accountable through socially ostracizing those who try to appeal to groups such as the Progressive Left and the Neoconservative Right, individuals such as Jeremiah Harding and Fakertarians have been allowed to not just enter their own voices into the movement with impunity, but even lead the charge in ostracizing groups like the Mises Institute from the mainstream of the movement.
Gatekeeping in the Liberty Movement, however, must be done in a specific way to prevent such individuals from continuing the leftward swing of the movement. This must start off with firstly adopting the Paleolibertarian and Proto-Hoppean principles of Murray Rothbard in the 1990s, with it also being made clear that these principles cannot be compromised over. Such views should include the Paleolibertarian views on Property Rights, the Role of Culture in the Liberty Movement, and most importantly Support for Secession. This must then be followed-up by instilling a strong culture of social and cultural conservatism in the movement, whilst also simultaneously reaching out to groups such as Paleoconservatives and the America First Movement to once again create the Paleo Alliance of the 1990s. Anything less than this will unfortunately not be enough to save the activist arms of the movement - these being the Libertarian Party, Young Americans for Liberty, and the Cato Institute - and though such a series of moves might never be undertaken, it merely goes to show how if a new movement is to be made it must have a form of gatekeeping to ensure its success and survivability.