A lot people who want a home theater just cannot afford the proper speakers or even the mounts to hold said speakers. In order to mimic, or try to make the best of a low budget situation, many people will take an old speaker set and just hook them up to a stereo amp; and to add insult to injury they wind up getting chains and hanging them from the drywall. The reasons why this is a bad idea are pretty obvious, but for health and safety reasons, let me explain.
It Can Be Deadly
Many old school speakers are very very heavy. Hanging these speakers from the ceiling in order to mimic the surround sound experience is also going to add weight. In many cases this is very dangerous because many ceilings do not have the strongest of beams running across it or even have any at all. Hanging a heavy set of speakers, a platform, and chains will tear out almost anything over time or if there's an earthquake. Having this heavy stuff hanging in a room is dangerous for obvious reasons because if they fell it would seriously hurt or kill someone.
Quality Is An Issue
The sound quality of these old speakers is definitely an issue. Many of these older speakers were built with paper and are prone to blowing out rather easy due to the lower quality construction. They also do not have the ability to play the depth of sound that you can get from modern speakers. To sum it up, bigger does not always mean better, and older doesn't mean it was built well.
It's Not Actual Surround Sound
Unless you have a stereo that can actually move the sound around between your speakers you are not going to have surround sound magically by placing these speakers around the room.