Actually, I take jury duty seriously, and my experience so far is that most people do as well. In fact, I would like to serve on a drug case - because it would give me an opportunity to refuse to convict under the rubric of jury nullification of unjust or simply idiotic laws (such as drug laws in the US). Usually, I am not selected because I am in a "wrong" socio-demographic group (white middle age male), but I was selected to a drug case some two or three years ago. The case was so flimsy that I knew what my verdict would be even before the defendant opened his mouth. I was worrying that I might be the only hold out, but the case was dismissed because the cop who made the arrest did not show up.
OTOH, I often hear that black jurors are more likely to reach guilty verdict in drug cases because they hate what drugs do to their communities. My response is that it is not drugs, but the criminalization of drugs, but most people do not fall for such subtleties.
The two cases that I was considered for yesterday were a medical malpractice and a murder - both serious matters, and my only concern was inconvenience (such cases usually take several days). I was not selected, however.
I guess my only objection to the jury system has nothing to do with the system itself, but with the nature of US politics. That objection is that people can decide the fate of individuals (often small time crooks) through jury trials, but they have little or no voice in deciding public policy issues that concern entire communities.
Wojtek