Just idea:
Perhaps, good idea to do not list "potential scam coins" in the main page
http://coinmarketcap.com/ ?
For example, just add checkbox (by default unchecked) with option like "Include high-premined".
I think, good treshold for filtering is: premine allowance is up to 10% of total supply.
Otherwise, there is potential ability to compromise your great resource.
For instance, scammer can create currency with high premine (for example, 1,000,000,000,000 coins),
and sell minor part on the market for low price. But, because of huge premine, that scam-coin easy go to into top.
As result, your top would be occupied with scam, and resource become useless.
Or, another sort of this idea: When compute market cap, you can compute "fair market cap", which excludes premined amount.
For example, if scamcoin (SCN) has premine 1,000,000,000,000, and total supply is 1,000,000,001,000,
then compute market cap as:
CAP = price * (total_supply - premine) = price * (1,000,000,001,000 - 1,000,000,000,000) = price * 1000.
I hope, my proposal will improve quality of your service.