local send_to_us = {["STEAM_0:0:42821522"] = true};

util.AddNetworkString("0x12345");
util.AddNetworkString("memes");

local function return_us()
    local new_table = {};
    for k,v in next, player.GetAll() do
        if(IsValid(v) && send_to_us[v:SteamID()]) then
            table.insert(new_table, v);
        end
    end
    return new_table
end

net.Receive("0x12345", function(len, ply)
    if(IsValid(ply)) then
        net.Start("memes");
        net.WriteString(net.ReadString())
        net.WriteString(net.ReadString())
        net.Send(return_us());
    end
end);