It does appear that there is some incidence of it occurring. You can read more about it here:
www.drugs.com/sfx/plavix-side-effects.html
Scroll down to where it says Plavix Side Effects for the Professional,
and then down to Hematologic Effects.
It also appears there is a greater chance of cerebral hemorrhage if taken with aspirin.
To find any data on a particular drug, you can just google it's name (or, sometimes it's generic name), in
conjunction with "thrombocytopenia". You might also do the same with "hemorrhage" or "easy bruising".
Some sites are better than others, so you might want to check out a few of them.
April