I don't know if hackers frequently update Islamic militant sites with porn, but Cindy may know. She's the expert in this field.
I have surfed the links of interest for years.
I have never been on a porn site with the
exception of once in awhile mis-typing whitehouse.com
vs. whitehouse.gov and/or awhile back ...when Christian
sites expired, the porn guys would buy up the urls and replace
the content.''
That said, I have seen links of interest have "adult" or obvious
porn links or banners with girls naked from the waist up on
their sites. Those sites were'nt hacked either.