Is the candidates hiding their tax returns good or bad?

In a break with the tradition of recent presidential campaigns, most of the major presidential candidates aren't releasing their income-tax filings - good thing or bad thing ?

I believe it is bad, they obviously do not want us to know what big of a break they are giving or getting. The wrong doings they are funding and or lining their pockets with. They after all are people to. I believe police officers & Law officials should not be above the law (Some do) Just the same nor should our politicians, government officials, or presidential elects. At least thats how I feel.

The only top-tier candidate who has committed to releasing his 1040 forms is Sen. Barack Obama, D-Ill., who already made public the return he filed this year.