Ask HN: Why are many Techcrunch and Mashable submissions from the same users?

There seems to be more and more techcrunch and mashable stories making it to the front page these days than ever before. Sure, they're legitimate news sources but what happens is people vote up the a given submission because of the topic, not because TechCrunch or Mashable are the article of record. Conversation ends up clustering around them rather than perhaps a more in-depth blog post (perhaps the original source of a news story) which leaves the community less informed (I think anyway) and less distinct from other sites. If I want TechCrunch and Mashable stories, I'll look at TechMeme. I always aspired that HN would be a place to discover blogs and more community-orientated links (individual's blog posts, startup's blog posts, etc). I began to look at who was submitting TechCrunch and Mashable stories that made the front page, and it looks to me like quite often it is a collection of the same users. To confirm I looked over: http://searchyc.com/submissions/mashable?sort=by_date http://searchyc.com/submissions/techcrunch?sort=by_date (you need to page through the results set to get a clearer picture, obviously) Particularly if you focus on submissions with >1 points, you can see the same names there. I'm not going to name them here, but you can see for yourself. In all the users I identified, all posted links from other sources too, but in a few cases they were mostly TechCrunch or Mashable. I'm not sure if those accounts represent someone with an interest in the authors (many outlets make extra payments to authors for reaching traffic goals on a given story), users trying to be opportunistic with vote-bait stories to improve their karma or just users who only read mainstream blogs... ...but I wondered what the HN community thought.