Our contract spells it out, work area must clear, move it, and give us a call when the area is clear, and we will re schedule, rushing in to a job like a bull in a china shop, can end up costing you some pretty good bucks, but then there is the thinking, if i ask them to move everything they will get someone else to do the job, so what is the big deal with moving a few things. The big deal is even if you tell they your not responsible, that will not let you off the hook, weeks, or even months later, don't be supprised if you get a call, the dinning room table my grandmother gave me is scratched, and they want $1000 to refinish it, remember you moved it to hang the new fixture.
For the guys not doing service work, this may not come up that much, but if your doing a lot of service calls, you already know how common this is.