Whether or not it is safe to use your debit card for online shopping depends on what website you are using.
AT&T is currently a reputable company. If you pay your cellphone bill using the AT&T website, that will probably be fine.
In addition to AT&T, the following businesses will not steal your money if you make a payment over the internet and using a computer:
If you think you are using eBay, make sure that small boring text at the top of your screen actually says,
Note that a computer (or a cellphone) cannot display stuff on a screen unless that same computer has a copy of the data it is displaying. If you are reading a newspaper article over the internet, then your computer (or cellphone) has a copy of that newspaper article. That makes it very easy for computer programmers to create a copy of a webpage. Hackers sometimes make look-a-like (copy-cat) webpages.
A hacker might make a perfect copy of the home page of eBay.com and display that copy at:
Some criminals act as middle-men.
- You will visit sarah-the-black-hat-hacker.com
- sarah-the-black-hat-hacker.com looks like gmail.com.
- The text at sarah-the-black-hat-hacker.com is the same as gmail.com.
- The buttons on Sarah's website are the same as at gmail.com.
- The colors on Sarah's websiteare the same as gmail.com
- Sarah, the hacker, records everything you type in (username, password, etc...). The hacker sends that data to gmail.com. gmail.com shows the hacker your email and stuff. The hacker will then relay your email to you, so that you do not get suspicious.
The moral of the story is: make sure it actually says
ebay.com in small boring text at the top of your screen. Ignored the pretty-colored large eBay logo on the webpage.
If the webpage mostly looks like ebay.com, but says my-god-its-full-of-stars.com in the URL box of your web-browser, then do not enter in your payment information.
If you can see something on a cellphone screen with your eyeballs, then it is very easy for a hacker to save that information. If you see a photograph of a dog on someone's webpage, then saving a copy of that dog photograph is trivial. In fact, your computer already has a copy of the dog photograph. The dog photo you see on your screen is stored in something named "the web-browser cache". Your computer automatically deletes things from cache on a regular basis. If your computer did not delete the cache, then your computer would save a copy of every webpage you have ever visited. That would fill up your hard-drive very quickly.
Let us have an analogy. What you see with your eyes on a computer screen is like the physical building a restaurant or a clothing store.
Computers are like magic in the sense that a hacker can make a perfect copy of the clothing store (or any other building) by snapping their fingers. A hacker can easily copy the visuals you see at google.com.
The copy of a clothing store's building would have the same branding, the same logo displayed; the same signage on the front of the building. The copy of the building would look identical.
However, the copy of the building will be located at a different street address.
"gmail.com", "google.com," etc... are similar to street addresses, or physical mailing addresses.
Always make sure that the street address (URL, or web address) is correct before you walk inside the store and give them your money.
It is possibly to make a copy of mcdonalds.com and put the copy at sally-sells-sea-shells-by-the-seashore.com. It might look like mcdonalds, but it is located at a different street address / mailing address.