Some statistics about blocks in 2012. The raw queries are provided below for clarification and reuse.

Type Count
Long term abuse 1739
Sock puppetry 961
Open proxies 201955
civility-related 45
Vandalism 1254
Spam-related 16227
Unblock (any reason) 2216

Queries

edit
mysql> /*SLOW_OK */
    -> SELECT 
    -> COUNT(*)
    -> FROM logging
    -> WHERE log_type="block"
    -> AND log_action="block"
    -> AND log_timestamp like "2012%"
    -> AND (log_comment like "%Long term abuse%" OR log_comment="LTA" OR log_comment="abuse");
+----------+
| COUNT(*) |
+----------+
|     1739 |
+----------+
1 row in set (2 min 14.01 sec)
mysql> /*SLOW_OK */
    -> SELECT 
    -> COUNT(*)
    -> FROM logging
    -> WHERE log_type="block"
    -> AND log_action="block"
    -> AND log_timestamp like "2012%"
    -> AND (log_comment like "%Abusing multiple accounts%" OR log_comment like "%sock puppet%");
+----------+
| COUNT(*) |
+----------+
|      961 |
+----------+
1 row in set (37.99 sec)
mysql> /*SLOW_OK */
    -> SELECT 
    -> COUNT(*)
    -> FROM logging
    -> WHERE log_type="block"
    -> AND log_action="block"
    -> AND log_timestamp like "2012%"
    -> AND log_comment like "%blocked proxy%";
+----------+
| COUNT(*) |
+----------+
|   201955 |
+----------+
1 row in set (1.98 sec)
mysql> /*SLOW_OK */
    -> SELECT 
    -> COUNT(*)
    -> FROM logging
    -> WHERE log_type="block"
    -> AND log_action="block"
    -> AND log_timestamp like "2012%"
    -> AND log_comment like "%civility%";
+----------+
| COUNT(*) |
+----------+
|       45 |
+----------+
1 row in set (1.68 sec)
mysql> /*SLOW_OK */
    -> SELECT 
    -> COUNT(*)
    -> FROM logging
    -> WHERE log_type="block"
    -> AND log_action="block"
    -> AND log_timestamp like "2012%"
    -> AND log_comment like "%vandalism%";
+----------+
| COUNT(*) |
+----------+
|     1254 |
+----------+
1 row in set (1.45 sec)
mysql> /*SLOW_OK */
    -> SELECT 
    -> COUNT(*)
    -> FROM logging
    -> WHERE log_type="block"
    -> AND log_action="block"
    -> AND log_timestamp like "2012%"
    -> AND log_comment like "%spam%";
+----------+
| COUNT(*) |
+----------+
|    16227 |
+----------+
1 row in set (1.26 sec)
mysql> /*SLOW_OK */ SELECT  COUNT(*) FROM logging WHERE log_type="block" AND log_action="unblock" AND log_timestamp like "2012%";
+----------+
| COUNT(*) |
+----------+
|     2216 |
+----------+
1 row in set (1 min 31.69 sec)