Drexel authorities try to be forthright when addressing violations. Thus, they're strict when they need to be—simply because they already warned the students. For example, students who drink when they should not be drinking are rarely punished, unless it's a nuisance to others (such as finals week). Security and police are more interested in breaking up a rowdy party to ensure everyone's safety—it is Philadelphia, after all. They have more urgent things to take care of in the city. So, as long as students restrain themselves from putting on a drunken display, all should be well. Although the drug scene is not that large, there have been instances when Drexel has enforced its "zero tolerance for drugs" rule. People have gotten expelled with no questions asked for drug possession and/or use. The University is very strict about drugs.
Aside from drinking and drugs, students rarely get in trouble for anything else. From time to time, students will get in trouble for vandalism in the dorms, which merely results in a fine. Other things you can get in trouble for are downloading copyrighted material and illegal parking.