Lapizuli - 9:54 pm on Jul 6, 2010 (gmt 0)
I'm no lawyer, and I don't know what jurisdiction you're under, anyway, but I think that libel (which may be the form of defamation you're thinking of, as your situation applies to published materials) has to be:
1) damaging to a reputation and
2) either a false or misleading statement, or a disclosure of something that shouldn't be disclosed (like an invasion of somebody's privacy or something contractually bound to nondisclosure, or whatever.)
And exhibit two...
From Wikipedia, referencing Milkovich v. Lorain Journal Co., 497 U.S. 1 (1990)
Opinion is a defense recognized in nearly every jurisdiction. If the allegedly defamatory assertion is an expression of opinion rather than a statement of fact, defamation claims usually cannot be brought because opinions are inherently not falsifiable. However, some jurisdictions decline to recognize any legal distinction between fact and opinion. The United States Supreme Court, in particular, has ruled that the First Amendment does not require recognition of an opinion privilege.
Since using the word "sucks" is (in any interpretation I can think of) expressing an opinion, and opinion is not a statement of fact, and assuming your title isn't misleading or an invasion of privacy, and this is not, um, taken to the Supreme Court, then any such statement wouldn't seem to be libel.
Just my off-the-cuff never-set-a-foot-in-law-school take on it. Whew! Why did I feel I had to include tons of legalese-style qualifications with that...?
But this is an interesting philosophical and legal issue, and one that will crop up more and more as increasing numbers of people express their opinions of products, agencies or people online, and potentially make or break reputations - and possibly huge economic and political sectors - with the click of a "submit" button.
It's unprecedented in a social unit of this (worldwide) scale. Since the opinions remain in databases indefinitely, even if they're changed or retracted, and since they reach a potentially infinite audience over the course of time, they can carry significantly more weight than opinions expressed in magazines, newspapers, and other print publications that had limited distribution and less ease of access. Which means an opinion now is not equal to an opinion in 1950, just as an opinion after the widespread use of the printing press wasn't equal to an opinion before it.
I wouldn't be surprised at some point in the future to see something on the order of "actionable due to nonsincere opinion propogated with bad-bad nasty malicious intent to defame" or some such mumbo-jumbo introduced. Not pleased, but not surprised.
It would be horrible, because one thing that's so nifty about the Internet is its equalizing influence. One person can effectively fell a corporation with a true word or a sympathetic opinion that appeals to the masses - thus making large, institutionalized public and private entities accountable to the people they influence. And individuals themselves become more accountable for what they say, because once it's published, it's set in stone, somewhere, whether it's in the index, in an archive, or on somebody's hard drive - which is a pretty organic way of making people act decently and honorably. Ironic, that electrons can accomplish that...!
All of the above is merely in my opinion, and should not be construed as legal advice, forever and ever, amen.