In my case my Norton blocked me when clicking on opening the chat board BEFORE I got in. I figured something was trying to take me somewhere other than the chat board and Norton caught it and stopped it.not necessarily. anti-virus 'add on features' provide 'warnings' about bad sites.
they also 'auto report' suspect sites.
and time to time I get quirky responses from various websites - 'access prohibited' and the like.
which is a different issue than obnoxious ads injected into the site.
This is behavior that I reported to the moderators a couple weeks ago. ....
I hope this helps.