"Illegal" is probably the wrong word to use here, since the iron ring is not governed by any municipal, provincial, or federal law.
I have a B.Sc. EE and yet work mostly in web/mobile software. I don't consider or present myself as a "practicing engineer" but I still wear the ring as a reminder of the obligation I have towards anything I create for other people to use. I probably wouldn't give it to my girlfriend to wear, but to each their own.
Actually it is the right word. The ring is a registered symbol of the Corporation of the Seven Wardens, and wearing or displaying one without their permission (via having been obligated) or attempting to sell one is illegal in exactly the same way that using any other entity's trademark without their permission is illegal.
That said, if you've been obligated and are working in a technical field, but don't really consider yourself an 'engineer' you can still wear it, so long as you hold yourself to the values it represents.
I should clarify: I attended a US university, so we didn't partake in the Ritual of the Calling of an Engineer. Rather, we participated in a similar ceremony for an organization called the Order of the Engineer. The Wikipedia entry on the Order of the Engineer alludes to what you're saying though; it mentions that they tried to bring the Canadian ritual to the US but experienced legal troubles including some related to copyright.
The ring is a registered symbol of the Corporation of the Seven Wardens, and wearing or displaying one without their permission (via having been obligated) or attempting to sell one is illegal in exactly the same way that using any other entity's trademark without their permission is illegal.
I have a B.Sc. EE and yet work mostly in web/mobile software. I don't consider or present myself as a "practicing engineer" but I still wear the ring as a reminder of the obligation I have towards anything I create for other people to use. I probably wouldn't give it to my girlfriend to wear, but to each their own.