Metal Can Transistor Question

[letsgocoyote]

Is there any purpose to the metal can part of a metal can transistor?

Reason I ask, is I typically build point to point and put my (to-92 plastic) transistors upside down so the plast part touches the bottom of the enclosure and the leads are supported off the ground.  Would doing this with a metal can transistor cause any shorts or problems?

[foxfire]

generally you don't want the metal can to touch anything.

[ErikMiller]

The can tends to be connected to the transistor's collector, so keep it away from anything you would not connect to the collector.