It is not very safe, and the protective measures of Internet cafes are not very good. Moreover, many Internet cafes install Trojans on their own machines. If you want to be in an Internet cafe, you'd better do something like a dynamic password or a U shield. Generally, you can call or go to the business hall to buy and sell on the spot. You can check online first, but don't trade, then call or go to the business hall to buy and sell.