There are pros and cons to both approaches. Databases are not really great for storing large blobs of data. Doing so will tend to use up lots of resources on the database (CPU, memory, hard drive space and network bandwidth between the database and web server). It will make the database backups much larger.
However, the big problem with storing the images on a separate file system (say on the web server) is that it is much more difficult to sync it with the data that is in the database. If a user changes a photo while a database backup is going on, who knows what state you will end up in. If you ever need to restore the database from a backup, it will be very difficult to sync up the images. You could also get orphaned images hanging around wasting disk space if you aren't careful.
IMHO, it is too much effort to maintain data integrity between the database and a file system, so I would store them in the database throw some money are the hardware so that it can keep up.