SaaS Filters

This company provides hosted and installable text filters.  They remove words, phrases, domains, etc.
Hosted is free.  Installable presumably has no latency.

Comprehensive Black List
Multilingual Filtering
Leet Speak (i.e. |-|ello)
Separators (i.e. h..e..l..l o)
Word and Phrase Filtering
Email Filtering
URL Filtering
Phone Number Filtering
Unlimited Messages
REST interface
Latency Depends Average < 1 ms
Throughput Depends 800,000,000+ per day
SaaS Hosted
Secure
Editable Lists
Multiple Lists
Real-time Updates
Java API
Testing Tool
Approval Workflow