Calls received late @ night. One after 9PM. Research on web - SSI is Survey Sampling International. Orem, Utah.
Checked Orem BBB website too. It is not an accredited company with Orem Better Business Bureau, but BBB does have reports on this company. They go by other names, Opinion Outpost & Western Wats (in BBB report). THE BBB also lists a contact principal: Ms Susan Evans (Business Contact).
There are opt out numbers to call by phone or do it online at http://www.surveysampling.com/general/received-a-call. If you do it online, consider sending a cc to Orem BBB.