Yes, Jobslinger can connect you to the MSP's sign up page when you open a job, but it would be obvious to you that you have moved away from Jobslinger to a company website. At that site you would be filling out a normal application with name, address, phone contacts, gender, height, weight, ssn etc. to become a registered shopper WITH THAT COMPANY to perform work. The work would be paid for by the company, not Jobslinger, and thus Jobslinger would never need your ssn for tax or any other purposes.