For some time now, the Internal Revenue Service has been shouting from the housetops about its stepped-up efforts to go after tax evaders, protesters and shelter promoters. And while it's hard to assess the impact of these efforts -- since even the agency doesn't really know how much tax goes uncollected -- there are some signs that the message is sinking in.

For example, earlier this month a 26-year-old man who had been resisting the IRS and making typical tax-protester-type arguments in the U.S. Tax Court to try to stave off collection of more than $3,000 in taxes and penalties, suddenly recanted all and promised to pay his tax, interest and penalties and never to "make these arguments in the future or appear in the [Tax] Court again," according to the Tax Court ruling.

The man's about-face, in which he quickly signed all required documents, persuaded the court to drop an additional penalty -- as much as $25,000 -- for making frivolous arguments or using a court case as a delaying tactic. Instead, he got off with a warning.

And the Tax Court itself seems to be getting tougher.

While it was willing to be lenient with the repentant 26-year-old, it is showing an increased willingness to hand out real pain to those whom it regards as abusers of the system.

In the case of a Florida software engineer this month, the court added a $20,000 penalty to the more than $300,000 in taxes and penalties already assessed by the IRS.

The engineer had failed to file tax returns from 1987 to 1997, telling the IRS that he and his wife did not work or reside "in any territory which is, or was, under exclusive federal jurisdiction." He also made other protester arguments.

Criminal charges against him were rejected by a judge who determined his non-filing and nonpayment were civil matters, but the Tax Court was not so sympathetic. It determined that the IRS had met its burden of proving fraud and upheld the agency's assessment of back taxes and penalties. Then it added its own penalty.

"Apparently [the engineer] expects that, if he feigns sincere belief, he will avoid penalties. . . . But he has persevered too long to have any credibility. Serious sanctions are necessary to deter him and others similarly situated," the court said.

Also this month, a federal court in Nevada held Irwin Schiff, a well-known promoter of what the Justice Department called "frivolous tax evasion excuses," liable for more than $2 million in taxes and penalties in a case involving unpaid taxes for 1979 through 1985.

Schiff argued that penalties shouldn't apply on the grounds that he is suffering from a "chronic and severe delusional disorder" that resulted in his irrational and incorrect beliefs pertaining to the federal income tax system. The court rejected that.

For many years Schiff counseled through books and a Web site that paying taxes is voluntary.

The court victories are good news for the IRS, which has sometimes struggled to convince the public that tax protesters' arguments are not valid. Last summer, a Tennessee jury acquitted a woman of criminal charges arising from her refusal to pay taxes on $920,000 she earned from 1996 to 2001. The basis for her refusal was a well-known protester tactic, but one the jury apparently bought -- a claim that the IRS hadn't shown her where in the law it said she had to pay.

In general, though, courts and most sentient Americans realize that the federal income tax is constitutional and Congress didn't forget to require that it be paid. Also, there is a growing understanding among honest taxpayers that when others don't pay, they have to make up the shortfall.

The Internal Revenue Service has ruled that employers who offer long- and short-term disability insurance can give their workers a choice each year about whether they want the value of the premiums excluded from their taxable income or included, raising their taxes.

The choice isn't the no-brainer it may seem. Workers who become disabled and claim the insurance receive the benefits tax-free if they have paid taxes on the premiums. If the premiums have been tax-free, as they would be if excluded from income, then the insurance benefits are taxable income.

The ruling "has the advantage of giving employees the flexibility to change their minds about paying disability premiums on a pre- or after-tax basis as they become more (or less) concerned about becoming disabled," according to an analysis by Martha Priddy Patterson of Deloitte Consulting. However, she cautioned that workers should understand that the choice must be made before the beginning of the "plan year," which may or may not be Jan. 1, and the choice that is in effect when a worker first becomes disabled will govern the taxation of the resulting benefits.