Objections?
That these were not written by Paul is not news to anyone, save evangelical fundamentalists. They belong to a class of writing known as pseudepigrapha, which refers to a text written under someone else's name, in order to give the document weight. The contest of the Pastorals is late 2nd century CE, and their purpose is to make it seem that Paul wrote against the Gnostics. They're about refuting heresy and defining ecclesiasical structure - the roles of bishops, deacons, etc., something that would have been of concern to a later, more developed church.
From Catholic Resources:
"Pseudepigraphic Letters" - The three Pastoral Letters, along with three other Deutero-Pauline epistles (Col, Eph, 2 Thess), are attributed to the apostle Paul, but were almost certainly not written by Paul himself. Rather, they are probably pseudepigraphic (i.e., written in Paul's name by one or more of his followers after his death).
http://catholic-resources.org/Bible/Paul-Pastorals.htm
Here is a paper written with the intent of exploring the issues related to literary forgeries in such texts (what was the intent of the authors? - etc.):
http://tinyurl.com/2eyfek6
Here is another, dealing specifically with 2 Peter, another such forgery:
http://tinyurl.com/3akqhee
Then there is the matter of interpolated material in the texts which are otherwise considered genuine, small tweaks and elaborations added by later Christian scribes, usually to better define some dogma or to bring the text into closer agreement with other New Testament texts or church doctrines. This article represents an older view of New Testament dating issues, but adequately relates some of the problems concerning interpolated passages:
http://www.ccel.org/s/schaff/encyc/ency ... iii.xi.htm
Western non-interpolations is a term related to textual variants where the Western text-type is shorter than other New Testament text-types. You'll notice these mentioned in some modern bibles like the NIV, where a footnote will read, "not found in older manuscripts." There is an astonishing amount of variation in New Testament texts, for all sorts of reasons, some deliberate, some not. The overall tendency of translators who favor the Western or Byzantine texts is to include everything they can find, regardless of how it got there, and where there are conflicting readings, to make a doctrinally based eclectic choice. It may not be the most sound choice, but it may be the one that best reflects what the translators believe. The KJV is a good example of such a translation.
http://wapedia.mobi/en/Western_non-interpolations
These are just a few of the issues related to New Testament criticism. It's not as simple as silversteinzero makes out, simply lobbing New Testament citations in an effort to put across a doctrinal point of view. Christians commonly have a very simplistic viewpoint, and seem to think that the New Testament was written in the order in which it appears in their bibles, by the persons whose names are on the books, and that these are reflective of the history of early Christianity. In point of fact, the gospels were among the last New Testament works written, with only a few of the pseudepigrapha coming after. The genuine letters of Paul (of which there are seven) came first. Paul does not mention the details of Jesus's life because he didn't know them: these were developed over a century later. Acts is a harmonizing fiction, designed to help place Paul in relation to the gospels in a way that was acceptable to then-current church orthodoxy.