Massive data use

What would cause my data usage to shoot up to 17.4 GB in only 10 days? I normally use 2 or 3 GB in an entire month, but my usage the last few months has been way down since I now use my iPad for FB and web browsing. I've noticed a severe battery issue on my Incredible over the last two weeks where it would die within 4 hours with no usage. To test it, I fully charged it and then unplugged it when I went to bed. Sure enough, it was completely dead when I woke up. I thought it was the battery so I switched batteries. Same thing happened. I don't use tethering and haven't changed any settings. Help!

 

Is that a free app? I suppose Lookout doesn't tell you data usage, does it? I'm worried that the big V is going to kick me off my unlimited data plan for abusing it. Wondering if I should call or will that put me on their radar?