I was reading the postings regarding the 3/10 year bar and I would like to have some things clarified.

How is this bar enforced? Does a person need to be caught as illegally present in the USA/overstaying in my case/ to be barred? I am not out of the US and do you suggest that if I try to enter e country on a visa I will be refused and presented with a bar?

How about voluntary departure, people who take VOD are not subject to any bars?

Finally, I have several friends who have overstayed for more than 2 years, immigated to Canada and were able to obtain visas at the US consulate and travel to the USA? In these case, why were they not barred?

And also, the INS was hugely criticized prior to recent overhauls for not being able to track alien exit, for not knowing who left and who stayed. How is the INS then able to tell you exactly how much time you have spent in the country and the exact date of departure then?

Please, address these issues.

Usually, if you are an overstay and you leave the country then when you try to re-enter the US the law is enforced, barring you from entering for either 3 or 10 years. Many people who are overstays just don't leave, overstays are forgiven if the person marries a us citizen. The friends that you have that left and then obtained visa's back, were they real overstays or did they have d/s on their I-94's?