Yahoo security is so bad at this point I am actively trying to get my clients to switch to Gmail.  I am actually at the point that I think I would probably rather have you get an Outlook(Hotmail) account, versus a Yahoo account.  This really is a shame because Yahoo does have a lot of good content.  I just don't trust them with my security.  I have upped my password to fourteen (14) characters, and removed all of my contacts. Out of the 1233 Contacts I have, 106 of them have at least one yahoo account.  Out of those 106 of them, I checked an online checker and SEVEN of them were listed as being compromised either on 2011.02.01 or 2012.11.23.  That is a terrible percentage, 6.6% if I did the math correctly(questionable).  I checked them using a site that will let you check up to 10 addresses at once.  It uses databases of leaked password lists to look them up.  So far I only looked up the Yahoo addresses I have as contacts, and then all of my own.  I know there are many more addresses that have been compromised than are on those databases because I get so many email messages from people who have accounts that are cracked and send out malicious links.

This page is a sub-page of the form letter that I use when I get those emails from accounts that have been cracked.

I am putting links here to other pages on my site that relate to Yahoo and email security in general.  Some of the pages I have the short codes so you can share them a bit more easily as well.

Yahoo! Account Help | Popular Abuse and spam articles

Yahoo! Account Help | - SLN3417 - What to do if your account is sending spam

Yahoo! Account Help | - SLN2090 - What to do if you are suspicious that your account is being used without your permission