I can't say for sure because I am not familiar with the site.

I have secondary menus in the side navigation of a couple of my own sites and visitors click on them.  On one site about 30% of the homepage clicks are on a secondary menu located near the bottom of the page (a popular free resource that brings in a lot of organic traffic but does not produce revenue).

Should we nofollow these links in the secondary menu?

In my opinion, definitely not.  If you nofollow them then the pagerank that would have flowed into them will be lost.  If you keep these links on your site let the power flow into them.

Thanks Dave.

That article surprised me.  I never expected google to have robots trained to hack at forms.  I wonder how many other robots are out there stuffing data into forms?

Might be Google knocking.... 

http://searchengineland.com/google-now-fills-out-forms-crawls-results-13760