I’ve been thinking lately about the legacies we’re all leaving behind on the social media sites we’re all rushing to be a part of, everything from LinkedIn to Twitter.

Here’s a self-written summary from the LinkedIn account of a supposed successful individual:

Financial services executive with close to 20 years of experience, starting with the day-to-day line valuation, trading, and investing of complex mortgage-backed instruments, debt, and interest-rate derivatives, including swaps, swaptions, options, and futures. With that critical experience, I have succeeded at an ever-increasing level of responsibility in managing a Company with $1 + trillion balance sheet.

My definition of success is the full utilization of my experience and abilities, and those of a carefully chosen and trained team along the lines of excellence.

And here’s some information from another individual’s LinkedIn profile:

15+ years of experience in IT, 10+ years of which is in Business Intelligence, Data Warehousing, OLAP and Web Analytics.

Architected, built and managed more than one multi-tera byte data warehouse solution in each of Oracle, SQL Server and Red Brick.

The first summary is from David Kellermann, the Freddie Mac CFO who hung himself this week.

And the second was from Devan Kalathat, the Yahoo engineer who recently killed his two young children, three other relatives, and left his wife in critical condition before killing himself.(This photo of Kalathat and his family is from his Flickr page, yet another social networking site he used.)

I found their profiles when I was researching the two men. I wondered what would drive individuals, many of us would think of as lucky, to commit such horrible acts.

When I came across their LinkedIn profiles I realized how much social media has changed our lives, the way we disseminate information, and potentially the legacies we leave behind.

Each of these men probably thought little of this when they were participating in the social media craze.

Just last month, Kellermann offered a recommendation on LinkedIn for an accountant that worked for him in the past, Jonathan Castro, a director at PricewaterhouseCoopers.

Jonathan is a detail-oriented and engaged member of the external audit team that has focused on information technology security and project governance at my Company. I have found Jonathan to be thorough, articulate, and value-added in his interactions with the Firm.

I wonder what Castro is thinking right now.

In the past, recommendations like this one, and the summaries above would have been hidden somewhere in a HR file. Today, little is hidden.

Is that a good or bad thing? I’m not sure.

LinkedIn and Facebook accounts will rarely let us know what their authors are really thinking. But reading the long list of accomplishments of two men who committed suicide makes you wonder how meaningful rat racing and corporate climbing really are.