Additional filtering hook during the parsing loop

I would love the ability for another module to be able to analyze the content being parsed, and reject it. Something similar to https://drupal.org/node/1945732

My use case is as follows: I can request specific feeds of data from partners, but they can't filter on all the criteria I need in order to determine if I want that content on my own site. I'd like the chance to be able to make that decision during parsing, and prevent a node from being created.