I would say that anything posted in a public forum is out there in the public domain and therefore free to use as one sees fit. This is assuming the code was originally offered up freely by the original author, and not posted up by another party. (example,... if someone posted the code of a library they had purchased, this would obviously not be the same issue)
Proper etiquette, however, would be to give proper credit to anyone's code you used. Claiming it was your own would be pushing it, and most likely would make people less willing to help in the future.
Proper etiquette, however, would be to give proper credit to anyone's code you used. Claiming it was your own would be pushing it, and most likely would make people less willing to help in the future.