Is it normal i think the universitys are some how getting my information?

I recently been looking up drills and disaster relief and other science information online. Not in school but as a hobby. Recently I been getting schools that have programs for these fields sending me information to join and I haven't recently signs up for a university. Do they have me on file or something or is this being fed to them from my computer? I heard that businesses like doing this to see what people buy but would a school do it?