I hear ya, Marie. But this issue comes up for me about once a year, if even that. I don't have an office per se (office out of my home), and I think each situation is dependent upon whether it appears someone is trying to steal a transcript from you or it's really a legit request to read and sign.
I'm working on a case right now that I reported depositions about 100 miles away, and the witnesses were not parties to the action, were unrepresented, and I will probably send them PDF transcripts to read and sign. I don't know how I can have them come 100 miles to read and sign, and I sure as heck am not going to travel that 100 miles myself to afford them that opportunity. I find it the lesser of the evils available to me and the most reasonable. It costs me nothing, too, which is better than actually printing a hard copy of the tript and having to mail it.
In my "practice" in Minnesota I have virtually no problem with attorneys attempting to steal transcripts. It is extremely rare. If I felt that was happening, I would certainly go to the wall with making them come to my office (the courthouse or whatever; I'd never have them come to my house -- ewwwwwe) to read and sign, and in the past when I've done that, they've never followed through and actually called to make the appointment. If they were a party, yeah, you bet, they'd never get a free copy. Otherwise, having an unprintable PDF might work in the original poster's situation and that is why I suggested it.
Mitz