Loads of stuff out there.
The SRS warning lamp is often triggered for relatively minor reasons that do not require any maintenance on the system. Any number of harmless acts can trigger the SRS lamp:
Driving the car through a large puddle, or being exposed to lots of rain
Swapping steering wheels
Removing the gauge cluster to replace light bulbs
Aggressive and/or track driving
Accidentally disconnecting an SRS component while hooking up electrical accessories, like an alarm or stereo
Pulling a fuse for the SRS system while performing electrical troubleshooting.
Bad seatbelt sensor in the belt receptacle (common failure)