For the last 3 years, I've been working as a contractor, providing services to a large company--let's call it "XYZ". I've chosen not to become a permanent employee of XYZ because my hourly rate as a contractor is much higher than what I'd get on salary for an equivalent position.
When I initially got the job, I was told that it would be a 3-month project, but due to pressing needs and my relatively rare skill set, I was kept on. Realizing that this was likely to be a long-term job rather than a quick contracting gig, and that XYZ was a much more widely known company than my contracting agency, I identified my employer as XYZ on Facebook. Over the past 3 years, I've gone through several different contracting agencies but continued to provide services to XYZ, so I've kept them listed as my employer.
Is it appropriate, from an HR perspective, to list XYZ as my employer on Facebook, LinkedIn, and other social media? I'm not actually their employee, and don't have benefits through them, but my contracting work with them is full-time 40+ hours per week, and now seems to be indefinite.
Some other Workplace.SE answers indicate that there's no problem with listing XYZ as my employer on my resume, but my social media content is more publicly available than my resume, so I'm wondering if it's appropriate professional behavior to present myself as working for XYZ, given that there's no way for me to identify it as a contract job on my Facebook profile.