Taiwanese citizen, labor insurance mandatory?

I am a Taiwanese citizen and I have been living in Taiwan for almost three years. I have some questions about Labor Insurance.

About a month ago, I randomly received a bill from the labor insurance bureau(LIB). This was the first time I had ever received a bill from the LIB. The bill was for 10 months of accumulated LI fees starting from last August(2010). Now the first question is, why did it start from last August? What triggers LI fees to start being incurred?

I understand that LI is similar to Social Security(FICA) tax in the U.S. But in the U.S., you only have to pay SS if you are employed. Which means that if you don’t work then you don’t pay FICA. Is this also true for Taiwanese LI? If so, why am I getting billed for 10 months worth of LI when I wasn’t working during any of those months?

Next question, what exactly do I get for LI? Like what do I get out of it and what are the benefits?

And finally, the most important question, is there ANY way to opt out of LI? I have my own views and misgivings about SS, it is something I’d rather not participate in. In the U.S., SS is absolutely mandatory and there is no way to opt out of it. Taiwan is probably the same way but I am just wondering if there is any chance or loophole where one can choose to opt out of LI and thus not have to pay the fees.

I think once you establish your citizenship and residency here, you will start getting the LI bills.

For me I never pay it because I am gonna move back to the states, however I saw on TV that if you don’t pay you will be fined and you HAVE to pay, can’t opt out. Is this true? It’s been like 2 years or more and I never pay it the sum seems pretty large, I don’t wanna have trouble entering Taiwan the next time I am coming back