What matters is this: an application, in and of itself, should never install an extension that modifies the system or otherwise diddles the runtime environment of other applications, without the express permission of the user. There are no exceptions to this rule.
Daring Fireball: Smart Crash Reports
This article is long, and it's sort of technical. But read it anyway, it's good to understand. But if you can't follow it at all, I'll cut to the key bit:
(I have suppressed the automatic installation of Smart Crash Reportsby placing an empty text file named “Smart Crash Reports” in myInputManagers folder. Using the Finder’s Get Info command, I lockedthe file, which prevents it from being overwritten by the “Smart CrashReports” input manager bundle.)
That might still be a bit tricky for some users. With a strong dose of caveat emptor, here's my step by step version.1) Open a terminal window (it's in Application/Utilties if you live in the dark ages. If you run Quicksilver open Quicksilver and type in "Term" or so until you find it. Or put it on your dock and aspire to be a real Unix weenie someday. :-))
2) Enter the following: cd ~/Library
3) Enter the following cd InputManagers
4) If 3) doesn't work you probably need to create the folder. mkdir InputManagers will do it. If 3) worked then skip to 5)
5) Enter the following: ls
6) If 5) returns this text "Smart Crash Reports" you already have it. If you know what you're doing at the command line, then delete the folder. (Full disclaimer - that's what I did - a rm -rf command. If you don't know what that means, I'm not going to tell you. If you do know than you don't need my help - RTFA beeyotch!) If you don't, let me tell you the safer way to trash it (using the Finder). Open the Finder. Go to your home folder, open the Library folder, and then inside there is the InputManager folder. Drag the folder named Smart Crash Reports to the Trash. This will junk it, but the next time you run whatever really ill behaved app it will reinstall it. Continue on to lock your system down. If 5) did NOT list the folder then continue to 7)
7) Back at the Terminal window enter the following: touch Smart\ Crash\ Reports
8) If you didn't do step 6 open the Finder window and navigate as described. Once you have a Finder window in Library/InputManager then select the file there named "Smart Crash Reports". Hit Apple-I (for Info). Click the "Locked" check box. Close the Info window, the Finder window and the terminal app. Now you are protected from "silent" installation of Smart Crash Reports.
Bonus note: If you have anything else installed in the InputManager folders you've got some other crazy thing running about. Apparently this is the same mechanism that PithHelmet uses. It sounds pretty clunky to me, but I Am Not A Mac Programmer. If you have something else in that folder and you don't recognize what it is . . . well that's bad. Drop me an email and we'll see what we can find :-)