-- Lets have a table containing names of players that cannot move
StopMove = {}

-- Also, lets assume that their name was already inserted into the table somehow

function OnPlayerMoving(Player)
    -- Search through the table as key-value format
    for _, k in pairs(StopMoving) do
        -- If the player's name happens to match a name in the table, stop them
        if Player:GetName() == k then
            -- Returning true means that the plugin has handled the player movement itself and the server doesn't have to perform any further actions
            return true
        end
    end
end

--- Map of PlayerName -> true for all players who should not be allowed to move
StopMove = {}
 
-- Stop a player from moving:
StopMove[a_Player:GetName()] = true

-- Enable player to move again:
StopMove[a_Player:GetName()] = nil

--- The hook handler for HOOK_PLAYER_MOVING, stops specified players from moving:
function OnPlayerMoving(Player)
  if (StopMove[Player:GetName()]) then
    return true
  end
end