The issue is the faucet itself, these guys have thousands of Bitcoin, but they are giving away too much free bitcoin ... 1 satoshi seems like a joke to many of you, a grain of sand, but imagine thousands of users grabbing it, if you look at the web you would see hundreds of different bots already built with one design and purpose - to drain FreeBitco's faucet.
Well, if that's the case, then what do you think, why Freebitco's ownership doesn't shut down their Faucet? Why do they keep running it? They should know that they are experiencing loss, so what should be the point to keep faucet alive? Maybe they give away much but they are also getting some back from gambling? I mean, some people roll it and then play dice.
They exist even now, it's impossible to stop them just with IP address or with a "fingerprint" system, we tried it all with so many versions, it's just so damn hard, you can't really stop these bad guys.
It shouldn't be impossible but might be hard. When someone rolls coins for 24 hours, it's 100% clear that it's not a human and it's a bot. Also, think about timeframes, even if bot rolls coins every 3 hour during the 24 hour period, that means that it's a bot because human sleeps at least 6 hours a day. Bot has to protect timeframes to not look suspicious and if bot protects timeframes, then that bot won't be beneficial for the bot owner, even if they exist a lot. Then there are other fingerprints that help them in this case. I think, there are many tools and possibilities that will help them to lower the negative effect of bots and to reduce their number.