Should overwrite be TRUE or FALSE by default?

[rgknight]

The help file for log_file says:

#' @param overwrite logical: whether or not to overwrite the file at
#' \code{file_name} if it already exists. Set to FALSE by default.

However, the default is actually TRUE: https://github.com/smbache/loggr/blob/master/R/log_file.R#L51

Which is the preferred behavior?