@lolapus4 They can't directly bypass FE, they take advantage of things that the server lets them do. For example, if you have a remote that transfers money to another player like
--NEVER USE THIS
remote.OnServerEvent:Connect(function(p1, p2, amount)
p1.Money.Value = p1.Money.Value - amount
p2.Money.Value = p2.Money.Value + amount
end)
and assuming the server checks the types of the arguments, a hacker could steal money from a player just by doing remote:FireServer(otherPlayer, -1000) to get themselves 1000 dollars. The solution to this problem is to check that the amount of money being sent is more than 0.
You shouldn't rely on local side protection, as hackers can just remove it and/or modify a script and remove the anticheat out of the script.
Flying is a hard issue to take care of, since the default movement system relies that the client is the network owner (handles the physics of the character, which also allows people to teleport the character) and, if you set the network owner to the server, when the client tries to start moving, the character won't move until the server receives the request, moves it, and replicates it back to the client.
