Scams exists both in the online world and in the offline world. Most scams in the online world involve transferring money to/from (fake) overseas bank accounts. Recently, Craig'sList has had some scammers expecting money transfers in exchange for online teaching services. I also used to get a lot of emails telling me someone's relative died and I needed to receive money on their behalf. But switching to gmail's better spam filters has almost entirely eliminated those.

I have not encountered anything of that magnitude on italki. Most not-serious members I've encountered on italki are looking for romantic relationships or are trying to collect email addresses. Once they collect email addresses, I'm not sure what they plan to do with them, but I haven't received any notices about money or bank transfers. Basically I would say italki doesn't have any serious or harmful scammers; however, you still need to be wary and never give out bank account information or offer to transfer or receive money on someone's behalf.