Significant Downwards moves today in markets

The S&P has lost 20 points in the overnight market. Asia and Europe are off in a big way. What's happening here?

Asian Market Indices
Index	Quote	Change	Change%	Local
New Zealand	3127.31	11.92	0.38%	17:31
Australia	4727.60	-13.40	-0.28%	16:47
Nikkei 225	9383.24	-58.40	-0.62%	16:00
TOPIX	829.56	-3.73	-0.45%	15:00
TSE 2nd Sec	1986.49	-0.13	-0.01%	15:00
JASDAQ	45.33	0.17	0.38%	15:11
Korea	1599.52	-12.36	-0.77%	18:03
Taiwan	7739.16	-17.15	-0.22%	13:46
Taiwan OTC	130.62	0.40	0.31%	13:46
Shanghai	3170.98	-119.18	-3.62%	15:15
Shanghai A	3326.10	-124.97	-3.62%	15:15
Shanghai B	244.44	-9.97	-3.92%	15:15
Shenzhen A	1230.11	-44.97	-3.53%	15:00
Shenzhen B	611.99	-12.16	-1.95%	15:00
SHSZ 300	3485.77	-143.86	-3.96%	15:01
Shenzhen comp	13287.37	-527.18	-3.82%	15:00
Hong Kong	22210.41	-401.39	-1.78%	16:01
HK CN Ent	13146.28	-299.81	-2.23%	16:01
HK Aff Crp	4093.17	-36.87	-0.89%	16:01
Singapore	2762.22	-30.62	-1.10%	17:10
FTSE ST China	289.64	1.49	0.52%	16:40
Vietnam	482.60	-20.81	-4.13%	11:01
Thailand	685.73	-9.96	-1.43%	16:59
Philippines	3089.82	25.52	0.83%	12:11
Malaysia	1270.61	-0.39	-0.03%	17:05
Indonesia	2393.52	-68.01	-2.76%	16:00
India	16854.93	-344.02	-2.00%	15:59
Pakistan	6529.44	4.09	0.06%	15:40