Large corporations often use instant messaging on a day-to-day basis.  They may utilize IMS to stay in touch with the sales department via IM, or the production team may use IM to coordinate video shoots across a small geographic area.  But, security concerns are widespread and wellfounded.

• Never post personal information on IM.
  Never respond to a message sent unsolicited by a user you don’t know.
• Be careful posting your screen name on Web sites.
• Do not click on links in messages that appear to be sent by someone on your buddy list.
• Check out the site IM Logic’s Threat Center to find out about the latest threats.
• Set your preferences on your IM client to only accept messages from your buddy list.  – MediaPost

The rest of the MediaPost article is helpful, especially the comments.  Take some time today to re-familiarize yourself with their online safety tips.