I generally reject any paper that I cannot get full access to.  This is because too many times have I seen papers making claims that are not supported by their methodology, especially in more controversial or politically charged subjects.  A common example is to study some socially unacceptable population, they will look to sample from known members which are often gathered due to court cases, and then they magically make generalizations to the general part of the population.  Imagine if most studies of men in the US only sampled from the prison population, could those results be generalized to all men?<p>Given that this data tends to be locked in the methodology section, which is quick to check if I have access, I tend to outright reject the paper as I cannot trust any claims made in the abstract.  Even worse are when there are papers you cannot trust at all because of overt biases of their authors (unless the findings are produced by others who do not share those biases, normally if you get people on both sides of some issue reaching the same finding you can be more confident in the results).