When it comes to the battle for dominance in the social media world, sites like LinkedIn and Twitter (News - Alert) need to be at their best. Facebook has captured the crown as the king of this particular market and the rest of the sites are all doing battle to come in a close second. Outages can be the death of a company like LinkedIn (News - Alert) because if users believe that there are going to be times when they can’t access their information, they are bound to move on. That’s bad news for LinkedIn, which suffered an outage earlier last week. The outage, apparently due to denial of service, meant that a domain sales page replaced the site’s home page for about an hour.

The outage couldn’t have come at a worse time, as LinkedIn is being taken on by a number of different social networking sites, just as it seems to have formalized its niche. Rupert Murdoch is even coming gunning for the site, as it appears that News Corp. is getting set to launch its own version a jobs-centric social networking site.

The company didn’t shed a whole lot of light on why the LinkedIn had gone offline for about an hour, beyond the admission that they had gotten a Denial of Service message. Industry insiders are saying that the site had actually been hijacked and that all traffic to the site was being sent to a network that is hosted by Confluence Networks. This is hardly the first time that the site has run into security issues and that alone could make some users decide that they need to be looking elsewhere.

Just a little over a year ago, there was a report that passwords for the site had been hacked by a Russian hacker. Some 6.5 million users we exposed in that particular incident.