Yes it was mobile phone data, I should have been more clear in the original reply. Looks like I can't edit it now.

I had no problems with data speed/cap before they phased out the unlimited tier. I was grandfathered in, but like I said, it was never the same. I primarily worked from the phone during that period and it was a constant struggle. Which is why it wouldn't surprise me if Verizon, across all of it's services, throttled traffic.