A friend of mine was lucky enough to be grandfathered into the Verizon Wireless unlimited data plan (which means he pays about $40 per month for unlimited data) but he has found that his data slows down if he hits over 10GB, though this isn't consistent. He also has to buy all of his phones outright (no upgrades for him) but this still works out to be cheaper for what he uses monthly.
Verizon Wireless no longer offers an "unlimited" plan. But Verizon home internet service does, but again, "unlimited" turns out to be limited in nature.
Here's a story about a man who's service is going to be cut if he doesn't stop "excessive usage" on his unlimited plan, which he pays $315 per month for. He's using 7TB a month (which I admit is insane) and has been told by Verizon that they will not provide him service anymore if he doesn't change to a business plan which "better suits him" or curb his usage. He says he isn't doing anything that breaks terms of service (like hosting a server) but they seem to be upset his volume of usage, not the type.
They're not legally obligated to continue the contract, but it still seems wrong. Why advertise unlimited if it's not truly unlimited? Why not advertise it as large but limited with some small print that directly says up to 6TB of usage per month? Most people would still go for it, I think.
As usual, Verizon is getting itself into trouble. It seems that it will be quite a long time before we see any huge reform from cable or internet companies, though.