They need to learn respect for other people and their belongings. I have a seven year old nephew and he understands not to touch it. I explained what all the equipment does and also how a turntable works. Although before I could explain records, he grabbed a brand new one with his whole hand. One side now had a nice thumb print, the other had four fingerprints. He thought of it as a large CD/DVD, I was mad, but once I explained how to handle records and it's been no problem. Besides, it was a just a record, my nephew is more important.
So, if a seven year old understands it, I would hope your adult friends can understand it. If not, use it as a teaching lesson - what it all does and how to use it.