If a carrier says you're getting unlimited data, they're not telling you everything

Give up any hope of ever getting an unlimited data plan from your wireless carrier.

It's over. Consumers have lost, and the carriers have won. There will never be an option for you to get unlimited data like you had in the early days of the smartphone.

That hasn't stopped carriers from trumpeting so-called "unlimted data plans." But if a carrier says you'll get unlimited data, they're leaving out an important part of the story.

Let's dive into the latest example. On Thursday, T-Mobile announced a unified, unlimited data plan. It costs $70 per month for a single user and $40 per line for a four-line family plan. Unlimited data, texts, and voice calls. One price.

Sounds great, right?

It is. At least until you read all the caveats:

• That unlimited data isn't truly unlimited. If you use too much data per month - approximately 26 GB according to T-Mobile - the carrier will "throttle" your connection and slow it down to a crawl until the next billing period. If you've ever been throttled before, you know how bad this is.
• Video streaming also takes a hit. T-Mobile's new plan limits you to standard definition video, not HD video. If you want HD video, you'll have to pay another $25 (!!!) per month. There are also a bunch of net neutrality issues related to prioritizing some video streaming services over others.
• Your unlimited hotspot data is limited to a slow-as-molasses 2G connection. You have to pay another $15 per month if you want 5GB of monthly 4G LTE hotspot data.

And now for the caveats to the caveats:

• Yes, most people probably won't go over 26 GB in a month.
• Yes, most people probably won't notice their streaming videos are coming through in SD on a small smartphone screen.
• Yes, many people never use their phones as a hotspot.

But while it's technically correct that you're getting unlimited data with this plan, it's not correct in spirit. Mobile data is useless if you can't use it at full speed. It'd be more accurate to say this is a 26 GB plan, not an unlimited plan.

Also, that $70 per month for one line is $5 more expensive than T-Mobile's current 6 GB plan, which is more than enough data for most people. As of September 6, individual T-Mobile customers who sign up are essentially paying more for a bunch of data they'll never use. That's great for T-Mobile, but bad for you.

I could go on and on. There are caveats to the caveats, which also have their caveats. And to complicate things further, AT&T and Sprint countered T-Mobile's announcement with moves of their own on Thursday. AT&T says it won't charge if you go over your data cap, but it will throttle speeds on some plans. Sprint has a new "unlimited" plan of its own. There are so many moving parts to this that there is no good, concise answer.

So instead of wasting your time, here's the TL;DR - you will always have to pay for high-speed wireless data. If you go over a certain limit, you'll have to pay more or deal with painfully slow speeds. There is and never will be such a thing as an unlimited data plan, at least until someone creates a revolutionary new way for us to wirelessly connect to the internet.

Today, "unlimited" just means you won't be charged more for going over a certain data cap. It doesn't mean you're guaranteed full-speed unlimited data.