Did Twitter Forget to Update its Copyright Year?

I noticed a strange thing today on Twitter’s homepage. Its already end of the first month of 2010 and Twitter’s homepage is still showing Copyright year 2009!! I don’t know if they have done this purposefully or just forgot to update the year. See the below screenshot. I am not an expert in Copyright matters, but we know that every website should change its Copyright year when a new year is started. Also it is not a compulsory thing to do so, but it is always advisable when your homepage is not just a static page showing some static tag, but showing realtime Trends. Like in the screenshot you will notice the Twitter’s homepage is showing latest trends such as Haiti, iPad, Serena Williams etc. Just to make sure this is not just a case with me, I tried to view Twitter’s homepage using a web proxy. I wanted to try new IP and see if this is same with everyone. I tried 2-3 web proxies and it all gave me same result. The copyright year on Twitter’s homepage is 2009 for everyone. As expected I couldn’t find © 2009 on a single popular social network/online websites. I tried Facebook, Google, Linkedin, Myspace, Orkut, AOL, Microsoft.com, Yahoo, Friendfeed etc but all of them have updated the copyright year to 2010. Surprisingly the Mixer Labs Geo API service Geo API which Twitter recently acquired also have copyright year 2009!!! Well in case Twitter has really missed to update its Copyright year, here is simple PHP script they must use to update their copyright automatically ;)

&copy; <?php echo date(’Y'); ?> Twitter
Code language: PHP (php)

I couldn’t find a single reason to think that Twitter has deliberately left Copyright year to 2009. What do you guys have to say about this? Does Twitter has deliberately left copyright year to 2009 or did they just forget it?