Do any convicted criminals residing in any prisons have legal access to the
InterNet?

Here in the UK, inmates of 'Open Prisons' can spend time
(unaccompanied) on the outside, so YES they can use Internet Cafes.

But we are very easy going on our Criminal Offenders ...

Why, we even forget to deport our foreign criminals at the end of
their sentences, murderers, rapists, the lot.

Yes, however the level of access generally depends on the individual
State or Federal prison system and the security rating/status of the
prisoner. Prisoners may have limited, or filtered access to the
Internet and be subject to varying degrees of monitoring. Prison
systems in USA, UK, Australia, etc. will usually have a publically
accessible policy on prisoner access to and use of computers and
internet access. If they don't, or they refuse to disclose it, then
speak to your local politician.

@Probono

Oddly I don't much care about the deportation
- they would be back anyway - probably within days

Keeping an eye on probationers is pretty much impossible, it beats me
why we bother.

There is a good argument for branding the foreheads of convicted
criminals, also (when it is certain) putting them into death camps
where they kill each other.

Personally I would divide crimes into two categories, one where people
are publically humilliated (dyed blue and put in the stocks every
Saturday) and the other where they are dumped on a remote island.

Actually, I would differentiate, one blue hand means you are
tolerated, two blue hands mean that you can be kicked (but not hit)
with impunity, a blue face means that you are a devoid of social
protection.

The islands could be similarly divided.

Hmm.. should they privatize high security prisons, I would be
interested, the television rights should pay for overheads.

Sadly, most of they guys that I've known who have done time were
pretty much Ok, passing dodgy 20 quid notes is stupid, not paying
alimony when you can't is inevitable (but one should say one is
skint), embellishment of HP agreements to help the client is standard,
minor or even major dope (hash) dealing is trivial.

The worst, in my view is a £5m fraud where he walked away.

From what I heard from the guy who did 'hard time', 50% of the inmates
deserve quick perfusion, and the other 50% are pretty Ok.

What bugs me is when psychopaths get minimal sentences, and 'when
unsafe' convictions get demonized.
Sir Roy Meadows is my first occupant of 'Cannibal Island'

Actually I feel rather strongly on the subject, as five years ago
something unpleasant happened, as it was, I had a bullet proof alibi,
and six weeks later worked out exactly what had gone on.

Unfortunately that would make the local plod look stupid, so they
faked the evidence - b*ggered with the mobile 'phone and lied at the
inquest.

I have a strong suspicion that, without that alibi, I would now be
stuck in nick. And you can be sure that an old time coder would be
found useful employment - access to the Net would be a cinch.