I can't wait for the multitude of sidechain forks that all compete with each other. Sidechains themselves require incentives to operate securely, such as fees and the continued security of the Bitcoin network, so I'd guess we'll start to see a lot of the same issues in sidechain space as we do in altchain space. I really don't think there's any difference between the two. You can also issue your own assets already on Bitcoin (e.g. coinprism, counterparty), so the notion of token issuance for use in general scamming will surely appear on sidechains as well. You can't out-technology human speculation in finance.