They can do if they are your network provider and provide the data you need to use if you are ot connected via wifi.
No it is not. It is for AT&T unless you "jailbreak" and "unlock" an iphone. Instructions to do this can be found on the internet.
Yes. AT&T offers services that allow the iPhone to access the Internet wherever there is a cellular data signal. Or, the iPhone can connect to a WiFi network to access the Internet without the need of an AT&T plan.
iPhone
No, you do not need to buy internet from AT&T when you purchase an iPhone. You can buy the iPhone unlocked or through other retailers and choose any carrier or plan that suits your needs. However, if you buy the iPhone through AT&T, it may come with specific plans or offers tied to their services.
AT&T requires you to at least get the ~$20 Internet package with the Iphone. You can also use your WIFI connection, but you still need the AT&T package
definelty not, however if you do not pay for unlimited internet, you will be charged for the use of the internet.
You can't use an iPhone with a prepaid account, unless it is a fake look-alike iPhone.
If you connect to an internet, no. Otherwise, due to AT&T's wireless, it costs money.
Lots of people have no contract and no access to the internet or anything.
You get faster internet then the original iPhone.
No you must purchase a data package from AT&T for $40.00, no excuses with them. But if you unlock it you do not have to pay for internet as long as you have wifi were you are
Short answer: No. Detailed Answer: You would first need to have a SIM card that is with AT&T. If it is with another carrier (such as T-Mobile, Sprint, Verizon, etc.), then you won't even be able to start the iPhone. If you already have AT&T, the iPhone can be used with extremely limited access. Actually, your iPhone won't be able to do much of anything. Even after putting in a SIM card, the iPhone will be limited to phone calls, text messages, and iPod features. Anything that requires an internet connection (which applies to just about everything else) will not work. If you try to go to a website, connect to YouTube, or even send a picture message, the iPhone will prompt you to contact your mobile provider. This is because the iPhone requires a very specific data plan that is only available through AT&T (so specific, in fact, that it is called the "iPhone plan"). After placing your SIM card in the iPhone, you would call AT&T, have them access your account, and tell them you are now using an iPhone. After the changes have been made, a restart of the iPhone is usually required. Once it reboots, all of the features will be available.