This friend is not the sort of person you can tell anything.

He is planning to let the Zim passport lapse as soon as he has finished transferring all his assets out of Zimbabwe (can only do it in small increments).

I have Italian,Filipino and Bristish Passport and also hold an HKID.
I have US visa on my Filipino passport so i can stay in US soil for more than 3 months up to 6 months. For short trips i use the Italian passport. I let my British Passport expire because the renewal fees are too high in my opinion.Although Italian passport requires me to put a a 40 euro stamp every year to travel outside the EU. That's easily bypassed if I connect through another EU country. But lately I've been flying out of Italy using direct flights so I have to pay 40 euros. I'm also eligible to get the HK Sar passport but i'm not sure because i already hold other citizenships. Filipino passport has the benefit of low fees and Visa free to some asian countries and the ASEAN area. Now my goal is to get a Return permit so I can go to china without applying for visas!!!

INSecureFlight has no bearing here - the data you enter can be completely fake and the TSA has no way to verify it. The passport information you use is transmitted ahead, not related to INSecureFlight and is part of a completely different program.

I've entered fake info in INSecureFlight without consequence. I hold US and Canadian passports and always declare my US passport to the airline even though I enter Canada with my Canadian passport or Nexus card - no one ever notices, and there are no stamps coming in or checks going out. However, if you're traveling somewhere and entry stamps and exit checks are used, you'd probably want to leave with the same passport you entered with.

Just remember to use the same passport to exit (esp in EU) else you will have to do a lot of explaining to Immigration.

I'm guess taking his money out as cash will require hiring dozens of trucks? :)

A friend of mine gave me a couple of Zimbabwean paper money. It had 12 zeros....
One Tillion Dollars!!! but I was told it was not even enough to buy a banana. :(

I have found that most countries I visit seem to check passports upon exit; the US seems to be the exception rather than the rule. Even Australia checks passports upon exit.

US CBP officers frequently stand at the gates of departing int'l flights to check your passports. seems to be doing it more and more often these days, not sure why. most of the time they just look at your passport and off you go. as I understand it, they do have the legal authority to do it, whenever and wherever they feel like. The funniest one I've heard was a passenger in front of me during boarding. The CBP officer asked to see her passport, but she said "I don't have one, the USA doesn't have exit border control" and tried to get past the officer to board the plane. Another CBP officer blocked the jetway door and told her "if you don't have a passport, how are you planning to enter Paris when you land?" The woman responded: "they are French, so they have the right to be rude, but you don't, you work fo the US government!" The two officers were not amused, to say the least. They eventually made her take out her passport from her carry-on case.

The US and the UK are two major exceptions to this rule (although this may change in the near future in the UK).

No outbound checks from Canada either.

if they have to do exit checks, they'll need to double the current number of immigration officers, no? hmmm.... probably a good thing for politicians, as it will make them look good for adding thousands of new jobs! :) (not to mention all the lucrative contracts that have to be handed out for construction of the proper facilities at every US int'l airports)

I have had my passport checked every time for the past 3 years when departing LHR.

Same situation when departing STN for Greece.

Even when departing LGW for a flight to Scotland, I had my passport checked.

Who was doing the checks? Airlines for pretty much all countries will check passport, but what I think most of us are referring to is Immigration / Border agents of the country checking passports.

And I am referring to immigration/ border agents too. They are the ones doing the checks. First you show your passport to the airline officials when you check in. You get your boarding pass and proceed to the departure area.

Before getting into the departure area, you go through immigration check (showing your passport again) and security screening.

As I travel with 2 passports, I occasionally have to show both passports, as I enter the UK on my UK passport and will later enter NZ on my NZ passport. The NZ passport will, naturally, not have an entry stamp for the UK, and I have been asked to show my UK passport as well, so the immigration official can verify that I entered the UK legally.

Now, don't tell me that the above procedure is done just by the airline, because it is not. The UK does check passports of departing travelers.

I see a lot of discussion about Malaysian dual citizens here.

Most of the legal facts have already been covered well here: Malaysia does not, except under extraordinary circumstances, allow adults to carry a second nationality.

If you are caught trying to enter Malaysia using a non-Malaysian passport, then you will likely forfeit your Malaysian citizenship. They are more likely to catch you if your name makes you a likely suspect (Malay name, Chinese name in Hokkien/Hakka/Cantonese variant, Tamil name). Also, of course, if you address the immigration inspector in Malay or speak English with a local accent.

However, a large number of people do manage to pull this off. The real numbers are of course difficult to know, but I know many people in this situation.

Here are the things to keep in mind:

1) Before your plane lands in Malaysia, your passport information is sent to Malaysian authorities by the airline, and NOT by the government of the country you just left. That means it doesn't matter what passport you showed to the immigration inspector on the way out, but only what passport you showed when you checked in with the airline. Switching passports between check-in and exit inspection is not uncommon, just be forthright with the immigration inspector of the country you're leaving if they ask you about it (and only if they ask).

2) Leaving the country for long periods (e.g. years) and having no stamps in your Malaysian passport will be seen as a priori evidence of shenanigans. Make an effort to use your Malaysian passport when you can, just to get some ink in it.

3) You should endeavor to have an exit stamp in your Malaysian passport from the country you most recently left, if possible. That means you should "launder" yourself in a third country between your country of residence and Malaysia, if you use your non-Malaysian passport in your country of residence. Singapore is the most popular country for this purpose: People fly from their homes in Australia or UK to Singapore, spend a day, preferably maneuvering to get the Singapore entry stamp on a different page from the Singapore exit stamp (they will do this if you ask nicely) and then fly or take the bus to Malaysia.

I wouldn't ordinarily go to such lengths to explain how to break a rule, but in this case it seems to be to be such an extraordinarily stupid rule that I don't mind.

For people who do not plan to live in Malaysia, or to travel extensively in Southeast Asia (where a Malaysian passport can save a lot of money on visa fees), it's really not worth the trouble. But for people who do have family in Malaysia, and who would like to return and live near their parents as they get older, I think it's criminal that the government makes it so difficult. And they wonder why brain drain is such a problem.

I hold a malaysian and aus passport for few years now, and haven't had trouble yet. I don't actually use my malaysian passport now, mainly using australian as it's less trouble to most other countries, even when entering malaysia.
however, i only go back for short visits and also don't plan to be there long term in the future.