"Porn addiction" is a bogey that the right wingers and religious nuts have dreamt up to justify their hatred of porn.
I came to this conclusion when I did the research for Exexexchurch.
http://www.exexexchurch.com/factareenies.htm
"The number of individuals for whom Internet sex can be problematic appears consistent with estimates made of this problem in the population at large. E. Coleman (personal communication, May 1998) estimated that 5% of the general population deals with issues of sexual compulsivity. The slightly higher percentage (8.5%) found in our study can be explained by the sample being entirely made up of individuals who go on-line for sexual pursuits."
The number of people who have a problem with porn use is relatively small and seems to correlate to the percentage of people who are addictive in general.
(Far more people (45% of Americans) regularly, compulsively use church... but no one complains about that. LOL)
That's not to say these people shouldn't receive help, and a link to a sex addicts help site seems quite reasonable. Of course, you could just put the text without adding the link...