Where is FTP Log file?

Like many of us I’m interested in tighten the security on my account these days.

Where can I find out when/who logged in to my FTP/SFTP account. I’m sure there is a shell command for that??

http://www.bloggerschoiceawards.com/blogs/show/18349/ (I SWEAR! I did nominate myself!)
2 free domains: [color=#00CC00]TODOMAINS[/color]

last | grep your_user_name