A strange access problem encountered today. Filters which restrict
access from outside the university network are common but I have never seen that
there are filters in place which restrict access to certain folders or files from
within Harvard. Here is an example, which still has this strange behavior while 
writing this:  the behavior appears with folders named "homework" or "hourly1": 


[knill@abel:] wget http://www.courses.fas.harvard.edu/~math21a/hourly1/practice1.pdf
--12:24:38--  http://www.courses.fas.harvard.edu/~math21a/hourly1/practice1.pdf
           => `practice1.pdf'
Resolving www.courses.fas.harvard.edu... 140.247.35.222
Connecting to www.courses.fas.harvard.edu|140.247.35.222|:80... connected.
HTTP request sent, awaiting response... 403 Forbidden
12:16:39 ERROR 403: Forbidden.


[knill@knill9:]  wget http://www.courses.fas.harvard.edu/~math21a/hourly1/practice1.pdf
--2011-09-24 12:23:42--  http://www.courses.fas.harvard.edu/~math21a/hourly1/practice1.pdf
Resolving www.courses.fas.harvard.edu... 140.247.35.222
Connecting to www.courses.fas.harvard.edu|140.247.35.222|:80... connected.
HTTP request sent, awaiting response... 200 OK
Length: 346413 (338K) [application/pdf]
Saving to: `practice1.pdf'
100%[======================================>] 346,413     1.38M/s   in 0.2s    
2011-09-24 12:23:43 (1.38 MB/s) - `practice1.pdf' saved [346413/346413]


Update: Nov 2. 2011:  the filters have gone.