There is a significant distinction here, but I opine that either behavior is unacceptable for an ISP. I'm reading this and the comments and imagining a telco switchboard operator listening to my call, and then randomly either breaking into my call to suggest I buy something (targeted ads), or then publish the full text of my conversations to any third party (history). And I do mean the full text. The link from home to your ISP must necessarily contain all the inputs you request of the web. This is not analogous to your call history; your computer is only making one "call" (to the ISP) and is having a long "conversation" (all your Internet activity) within that "call".

Disclaimer: I'm not very proficient at how the Internet works at this level. My comment's making it sound more and more like a pen register.