1. Proxy Based
2. Text Content Filter
3. Image Content Filter
4. Page Caching
5. Load page first before filtering
   1. text filter ok
   2. image filter not ok
      1. able to filter images within image tags
      2. cannot filter images in scripts
   3. redirection can be implemented
6. Filter requests on the fly
   1. text filter not ok
      1. not able to extract all text components
   2. image filter ok
      1. filter images within