This is a very good and very important question. Now that a lot of personal information is being moved to online sources it is good to consider how safe it actually is to make purchases online. The Internet is designed in a way to grant access to any user, and any user with the special knowhow can take advantage of this system and steal personal information from web sites. You can however give yourself some protections such as a computer security program. It is also highly recommended that you restrict your shopping to sites that make clear their security policies and go to great lengths to protect your data.
Shopping online does pose some level of risk of identity theft. Even though most sites, both big and small, have installed very secure protective measures against cyber invasion, it can still happen. So if you shop online, you should be at least aware of this risk and concede that it can happen to anyone. There are a few rules you can follow. If any site requests your credit card information and you are not buying anything, don't give it. Don't click on unknown links on websites you are unfamiliar with. And most importantly, it is advantageous to do your shopping only with businesses that have received accreditation from various accreditation bureaus such as the BBB (better business bureau).