Well ... for the record, I was working out in Germany for the launch of
the Mannesman "D2 Privat" network when it was launched in the early 90s.
Not long afterwards it was discovered that GSM1800 handsets being sold
in Germany for the E-Plus network were turning up and being used on the
One-2-One network in the UK. I know because I was asked to buy some
prior to a trip back to England.
It didnt take long for the network operators to find out about this and
start protecting their commercial interests by getting in to the handset
locking business.
I believe there was a big row about it within the ITU and/or the GSM,
and their point of view was that these locked handsets were technically
illegal GSM terminals and that the operators were violating the terms of
their network licences by registering them.
As a child of 12 could have predicted, the spineless regulators did
nothing useful about this for the next 25 years, which has led us in to
the mess we are now in.
Were it ever thus ...
AT