The posts about cats chattering made me wonder if anyone else has
heard their cats make protest squeaks.

Betty can make a really high-pitched "mreeeek" type squeak.  It's a
bit hard to describe, but it sounds like a cross between a lady
squealing at the sight of a mouse, and a rusty door hinge.

She doesn't make this sound very often, but the type of situations in
which Betty does make it is very consistent.  She makes this
particular sound when she's being restrained from something she really
wants.

For example, I carry her to the screen door to show her the birds
outside.  Mreeeeeek!  Or it's morning, and I've been half-asleep
kissing and mauling Betty for 20 minutes straight.  Mreeeeek!

The squeak of protest is usually not accompanied by a physical
struggle.  The vocalization is enough to communicate what she wants.

The funniest time Betty did this squeak was after I was away from home
for two days.  After the first and second days of my not coming home,
Betty must have given up on me.  When I got home, Betty was not there
to greet me at the door.  I went to the bedroom, where I found a bed
lump.

"Betty?" I asked the sleeping lump.  The lump started struggling
desperately at the covers trying to get to the source of that voice as
quickly as possible.  "Mreeeeeek!!"