in reply to "This site is not secure" warning message

The root cause problem is simple:   although PerlMonks now attempts to use SSL, as most other sites do the certificate that it is now presenting is not valid.   Neither does the site appear to be using SSL consistently yet, as some pages show the lock but others do not.   These are all issues that the site owners/administrators must now work through as all of us have had to do from time to time.