IANAL, and nothing that follows is legal advice, but I'm a legal assistant who's done IP work occasionally.
As far as I know, no, it's actually a bad idea. It is supposed to be the year of first publication per 17 USC §401(b)(2).
The 'reason' people seem to suggest updating it is to avoid the impression that the site's not been updated, but as far as I understand things, to do so falsely suggests that the first time you published whatever you're putting the symbol on is the current year - thus opening up yourself to prior-work claims.
One likely might counter with Internet Archive snapshots (I've seen the IA cited in court briefs, even sometimes by judges - although again IANAL and this is not legal advice), but it's still dumb IMO to specifically move your year forward on New Year's.
all we need is for a community to get behind the idea, of some sort of id system, create a 'twitter enhancement suite', and have it apply checks to accounts for people, based on the community, and not twitter.
