If you have a problem with a corpmate looting "your" can, maybe you are in the wrong corp. Capitalist piggy corps self destruct over issues like that. Communist corps that work for common good do not. Seriously, think hard about who you want fighting/killing with you. If you can't trust your corp "brother/sister" then you may have a corp issue and not a free loot issue.
As it is, it works. My corpmate hollers that he has a can needing hauling.. it doesn't matter what squad I'm in I can go help. Sometimes there is a need to be in different squads so no need to swap and switch or use PW for all cans etc. If someone was to join your corp to rip it off ala steve, they could only get away with very little before being caught and dismembered.