Most sites that I get in and get out are fast to process but some, not so much

I've been noticing a weird trend around my network, most sites are generally fast to load in and sites that have *ahem* pirated content onto them are slow to load. Weird thing also is, Twitter is fast to load however the contents, like the buttons and posts, don't buffer in.

I don't know if this is a DNS problem or some other weird magic here.