$ cmd='use LWP::UserAgent;
  print length(LWP::UserAgent->new->get
  ("https://www.facebook.com/media/set/?set=a.243839749129060.1073741851.158694774310225")
  ->decoded_content), "\n";'

$ /usr/bin/perl -e "$cmd"
158

$ /opt/local/bin/perl -e "$cmd"
20937

The error in the former case is this pack of lies:

Can't connect to www.facebook.com:443 (Host is down)

LWP::Protocol:: https::Socket: connect: Host is down at /Library/Perl/5.16/LWP/Protocol/http.pm line 51.