What recourse does someone have?

[ahanu]

if they experienced problems with slander and harassment in Yahoo Answers? I know these actions are against Yahoo terms of service, but will Yahoo do anything about it if the problem is reported?

[alleyne]

You can report these as both slander and harassment (illegal), and if one or two other users also report them (most likely!), the comments will be deleted, and a notice sent to the user. Too many illegal activities will result in the suspension of the Answers account, or even the entire Yahoo account, including e-mail.
To feel better about it, also report this directly to Yahoo. Go to your home page or your mail page, click on Help - at the bottom is Contact Yahoo. Click on that.After copying the link to the question or answer, (and the user's profile too), paste it in the body of the email. Then send the message to the Y!A Team explaining your reasons at the following address:
[email protected] (note that the "e" has been left out)

Best of luck, and do not let the 'nasties' get you down - there are some very immature people here who delight in their anonymity.