Can't block caller ID in Massachusetts?

[David Mazieres]

My last phone bill said that Nynex is now giving out people's names in
addidtion to their phone numbers over caller-id.  I therefore called
Nynex and told them to block caller-id on my phone line.

They said no problem, but...  They said nothing I can do will block it
when I call 800 numbers.  "The people with 800 numbers have special
software, and there is nothing you can do to block your identity when
calling them.  Not even *67."

Wow.  Maybe I'm not paranoid enough, but I never expected this.  I can
never again call an 800 number anonymously to get information about
something unless I go out to a pay phone.  What an incredible
inconvenience, and how truly depressing.

I know 800 number owners probably used to be able to get lists of
calling phone numbers on their phone bills, but this is less
disturbing as it would take significant effort to match up the lists
after the fact.  I just want to be able to call up companies and say,
for instance, "If I buy your product, can it do X?" as opposed to, for
instance, "I'm stuck with your product, can it do X?".  People are
often more helpful in the former case.  Now, though, they'll know
exactly who I am before they even say hello.

David