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. http://www.viclovan.com/downloads-and-links/email-password-cracked-form-letter-for-reply-to-all/ http://goo.gl/hs7Yr
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 http://www.viclovan.com/downloads-and-links/email-password-cracked-form-letter-for-reply-to-all/yahoo-email-security-and-related/yahoo-account-help-popular-abuse-and-spam-articles/ http://goo.gl/awzBe
Yahoo! Account Help | - SLN3417 - What to do if your account is sending spam http://www.viclovan.com/downloads-and-links/email-password-cracked-form-letter-for-reply-to-all/yahoo-email-security-and-related/yahoo-account-help-sln3417-what-to-do-if-your-account-is-sending-spam/ http://goo.gl/rPfiF
Yahoo! Account Help | - SLN2090 - What to do if you are suspicious that your account is being used without your permission http://www.viclovan.com/downloads-and-links/email-password-cracked-form-letter-for-reply-to-all/yahoo-email-security-and-related/yahoo-account-help-sln2090-what-to-do-if-you-are-suspicious-that-your-account-is-being-used-without-your-permission/ http://goo.gl/AX8cq