Too many wires for one connection point

Too many wires for one connection point

 I see this much too often -- most of the time a breaker is designed so that ONE ( 1 ) WIRE can be SAFELY connected. As you know electricity creates heat, metals expand with heat and shrink as they cool,, SO that means over time, even a typical connection has the potential to loosen up.
Now - if there are two or more wires.. HOW MUCH ARE THEY MAKING GOOD CONTACT?? Isnt it also obvious that if it doesn't make good contact , not only are you weakening any possible protection the breaker can provide for the circuit, but your creating a hot spot - which can lead to fire..
Unfortunately - there are many shody workers who will connect cheat connections such as this. Famous last words : " it hasnt burned down yet...."