To all intents and purposes - these virtual black holes only seem to exist in Europe.. and only visible by those who do not have the appropriate paperwork to hand..
Oh I don't know. I was on the way back from Big Bear over the overcast and found a nice hole to get low enough to get below
Actually this problem I'd think was more of a USA problem. In the UK we (as in Non instrument rated / qualified) pilots are prohibited from flying VFR OTT, whereas in the USA it is allowed.....
Still, I wouldn't do it without an instrument qual.